Supplements: Protein Powders, Ergogenic Aids
Linas JuozėnasShare
Supplements
Understand what a supplement can contribute, when it may help, and how to choose it with confidence.
A protein powder can make breakfast easier. A dependable vitamin B12 supplement can meet an essential need in a vegan diet. Creatine can support certain training goals. These are useful contributions, but they solve different problems.
The challenge is recognising the difference between a product that meets your needs and one that simply adds expense or complexity. Attractive packaging, a long ingredient list and a convincing explanation of a biological mechanism do not establish that a product will improve your health or performance.
This guide brings the main decisions into focus: the purpose, the evidence, the amount, the product's quality and its place in ordinary life. It covers general adult use, with particular attention to protein powders and sports supplements.
Name the nutritional gap, practical difficulty or performance outcome.
Check research on the ingredient, amount and situation that matter to you.
Consider ingredients, quality checks, health, tolerability and cost.
Supplements have different jobs
In everyday language, “supplements” often includes everything from vitamin tablets to protein shakes and sports drinks. Their legal classification can differ, but a practical first step is to ask what each product is intended to do.
The IOC's consensus on sports supplements distinguishes nutritional provision, convenience and performance-related uses. It emphasises assessing needs before choosing a product.[1]
Meet a nutritional need
A nutrient may need a dependable supplemental source because of diet, absorption, life stage or an identified deficiency. The goal is adequate provision.
Make eating more convenient
A powder, drink or portable food can help when shopping, appetite, preparation or training schedules make ordinary meals difficult.
Support a specific task
A performance aid may help with a particular kind of exercise. Its usefulness depends on the task, the protocol and the individual response.
These reasons deserve different expectations. Meeting an essential nutrient need remains worthwhile even if you do not feel an immediate change. A performance product, by contrast, needs a credible connection to an outcome you actually value.
Write the purpose in one sentence: “I need a reliable B12 source,” “I struggle to include protein at breakfast,” or “I want to assess creatine during a consistent strength programme.” A clear sentence makes the next decision much easier.
The evidence belongs to a use, not just an ingredient
This overview is a starting point. The sections below explain the evidence, limitations and practical considerations behind each entry. None is a universal shopping list.
| Product or ingredient | Potentially useful role | Main qualification |
|---|---|---|
| Protein powder | Convenient protein when intake or meal organisation needs support. | Its contribution depends on total intake and the chosen protein source. |
| Creatine monohydrate | Support for repeated intense efforts and resistance training. | Expect gradual changes in muscle stores; consider water-related weight changes. |
| BCAAs | Supply three essential amino acids. | They provide only part of the amino-acid material needed for new protein. |
| Caffeine | Alertness and some exercise-performance benefits. | Individual response, total intake and sleep matter. |
| Beta-alanine | Support for selected sustained, high-intensity tasks. | Usually requires regular use over weeks; tingling is not proof of benefit. |
| Dietary nitrate | Possible benefits in some exercise tests. | Effects vary across outcomes; product nitrate content matters. |
| Sports drinks and gels | Convenient carbohydrate and, in some products, electrolytes. | Match the product to the duration, demands and conditions of exercise. |
| Vitamins and minerals | Dependable nutrient provision where needed. | Additional intake is not automatically beneficial once needs are met. |
Ask what was actually measured
Feeling more stimulated, showing a change in a blood marker and improving a race result are different outcomes. A brief rise in muscle protein synthesis is informative, but it does not directly measure months of muscle growth.
Look for a relevant comparison: the same training with and without the supplement, similar total protein intake, or a placebo under comparable conditions. Consider the participants, study length, uncertainty and whether independent research points in the same direction.
Funding and declared interests deserve attention, especially where products are commercially important. They do not settle a study's validity by themselves; methods, transparency and replication still matter.
Start with the day's food and the training goal
Protein supplies amino acids used to maintain and build body tissues. A powder is a concentrated food ingredient that can contribute to that supply. Its value depends on what the rest of the diet already provides.
The ISSN position on protein and exercise describes approximately 1.4–2.0 grams per kilogram of body weight per day as sufficient for most exercising individuals. This is total protein from food and supplements together, not an amount to add as powder.[2]
The appropriate intake varies with training, age, energy intake and health. A general sports-nutrition range is not an individual prescription.
More protein has diminishing returns
A meta-analysis of 49 resistance-training studies found that protein supplementation modestly improved average gains in muscle size and strength. Its statistical model suggested diminishing additional benefit around a total intake of 1.6 g/kg/day.[3] That estimate is not an exact biological ceiling for every person.
The practical question is whether a supplement fills a meaningful gap. If meals already provide adequate protein, another shake may add little relevant benefit. If breakfast regularly contains very little, a suitable protein food or powder may solve a useful problem.
Distribute food in a manageable way
Include substantial protein sources across meals. Total intake and the meals surrounding training matter more than meeting a narrow post-workout deadline.[2]
Beans, lentils, tofu, eggs, fish, meat and dairy can all contribute within a person's dietary choices. Enough total food matters too: a protein shake alone cannot provide all the energy, carbohydrate, fats and micronutrients needed for an active life.
Choose protein powder by composition and suitability
Protein sources differ in amino-acid composition, digestion and processing.[4] Finished products also differ in flavourings, sweeteners, added nutrients and the amount of protein in a serving. The nutrition label is more useful than a premium-sounding name.
| Type | What it is | What to consider |
|---|---|---|
| Whey concentrate | A milk-derived protein ingredient. | Often retains more lactose and fat than isolate; composition varies. |
| Whey isolate | More extensively filtered whey. | Usually lower in lactose; still contains milk proteins. |
| Hydrolysed whey | Whey partly broken into smaller peptides. | Compare tolerance, taste, price and evidence for the claimed advantage. |
| Casein | A milk protein with relatively slower digestion. | Choose it if it suits your meals; a bedtime shake is optional. |
| Egg white protein | Protein obtained from egg whites. | An alternative to dairy; unsuitable with egg allergy. |
| Plant proteins | Soy, pea, rice and other sources or blends. | Compare protein content, amino-acid profile and relevant allergens. |
Lactose intolerance and milk allergy are different
Lactose intolerance concerns digestion of milk sugar; milk allergy involves an immune response to milk proteins.[5] A low-lactose or lactose-free whey product is therefore not a suitable substitute for someone who must avoid milk proteins.
A scoop is not a universal unit. A serving weighing 30 g may contain substantially less than 30 g of protein because the powder includes other ingredients. Read grams of protein per serving and the stated serving weight.
Sweeteners and thickeners are not automatically a reason to reject a product. Taste, individual digestive comfort, allergen information and the overall formulation are more useful considerations than assuming that every additive is harmful.
Use the source that fits the meal and the person
Plant protein can support training
A twelve-week study of habitual vegan and omnivorous young men found similar muscle and strength gains with resistance training when protein intake was matched using soy or whey supplementation.[6] Participants were not randomly assigned to their dietary patterns.
This supports a carefully organised plant-based approach. It does not mean that every powder or serving provides an equivalent amount or balance of amino acids. Look at the actual diet and product.
Collagen has a different amino-acid profile
Collagen should not be treated as interchangeable with a complete protein source for muscle support. In a short trial in older women, whey stimulated muscle protein synthesis more strongly than collagen.[7] That finding concerns muscle protein synthesis; it does not answer every question about collagen's other possible uses.
Make the powder useful in ordinary food
It can be stirred into a suitable yoghurt, blended with food you enjoy or used as a drink when a meal is inconvenient. Check mixing and storage instructions. Adding milk, a fortified plant drink, fruit or oats changes the finished meal's nutrition.
A protein-only powder is not necessarily a nutritionally complete meal replacement. If a shake regularly replaces lunch, consider what is missing from the rest of the day and whether a more substantial meal would work better.
Compare value by the contribution you use
For a simple price comparison, divide the container price by its total grams of protein, then multiply by the amount being compared. For example, an illustrative €24 bag weighing 1 kg and containing 75% protein provides 750 g of protein: about €0.80 per 25 g of protein.
That arithmetic does not assess flavour, testing or suitability, but it prevents package size and scoop size from disguising the price. Compare with ordinary foods you would realistically eat.
A well-studied option for particular training goals
The body makes creatine and obtains some from food. Muscle phosphocreatine helps restore ATP during contraction. Supplementation can increase muscle stores and support repeated high-intensity efforts and resistance-training adaptations.[8]
The relevant question is whether those benefits match your activity. Evidence from repeated intense efforts does not establish an advantage for every endurance event or an improvement in every aspect of health.
A steady daily approach is usually straightforward
Creatine monohydrate, commonly 3–5 g daily, is a well-studied approach in healthy adults. Without loading, stores build over roughly three to four weeks. Larger, divided loading amounts can work faster but are optional.[8]
A familiar meal can help you remember the daily serving. Check creatine content across products so a blend does not create an unintended duplicate.
Prefer a clear ingredient and a clear expectation
Monohydrate is the reference form used extensively in research. A more expensive form needs evidence of a useful advantage; claims about solubility or absorption do not establish superior training results.[9]
Creatine does not replace training. Its place is alongside a programme you can sustain, adequate food and recovery. Decide which outcome you will assess, such as performance across comparable sets over several weeks.
Claims about memory, disease treatment or other outcomes require their own relevant evidence. A study showing a strength benefit cannot establish those additional claims.
Water, digestion and kidney tests need context
Early weight changes are not all new muscle
Muscle water can increase after starting creatine, particularly with loading. This can affect scale weight without representing fat gain. Large single servings can also cause digestive discomfort.[9] Consider these effects when body mass matters to a sport or when interpreting early progress.
Creatine has not been shown to cause dehydration
Experimental research does not support the common claim that usual creatine supplementation causes dehydration or muscle cramping.[9] Drink appropriately for exercise, weather and your needs; there is no reason to force excessive water simply because you take creatine.
Creatinine is a marker that needs interpretation
A 2025 systematic review found a modest rise in blood creatinine in some studies without a significant reduction in glomerular filtration rate overall.[10] Creatine turnover can influence creatinine, so a change in that blood marker alone does not prove kidney injury.
Equally, an abnormal test should not automatically be dismissed as “just creatine.” Tell the clinician what you take so the result can be interpreted with your history and other findings. Existing kidney disease or an unresolved kidney concern needs individual advice before supplementation.
General adult research does not justify assuming that a product is suitable for every life stage or medical situation. Use advice matched to the person and the reason for taking it.
A signal for building protein still needs building material
Branched-chain amino acids are leucine, isoleucine and valine—three of the nine essential amino acids. Leucine participates in signalling that influences muscle protein synthesis, but forming new protein requires adequate availability of all the essential amino acids.[11]
A product that emphasises leucine content or a particular BCAA ratio has not thereby shown that it improves long-term muscle growth. The rest of the amino-acid supply still matters.
Acute research is not the same as a growth programme
In a small study of resistance-trained men, BCAAs increased muscle protein synthesis over several hours compared with a placebo.[12] It was not a long-term muscle-growth trial or a direct comparison with a protein-matched serving of whey.
This distinction avoids two misleading extremes: BCAAs are not biologically inactive, and a measurable short response does not establish a meaningful extra benefit for someone already eating sufficient protein.
Choose a solution that supplies what is missing
If protein intake is inadequate, a substantial protein food or a suitable complete protein powder usually addresses a broader need than three isolated amino acids. BCAAs already occur in ordinary protein foods and many powders.
A full essential-amino-acid product supplies all nine essential amino acids, but it still needs a clear purpose. It is not a complete meal and is not automatically necessary when adequate protein is already available.
Before buying an amino-acid drink, compare its contribution and price with a meal or protein source that fits the same situation. The useful question is what it adds to your existing intake.
A possible performance benefit with a sleep trade-off
Caffeine can improve alertness and some exercise outcomes, particularly endurance performance, but responses and side effects vary.[13] Feeling intensely stimulated is not a reliable measure of how much performance has improved.
Sports studies often use doses based on body mass, sometimes large enough to exceed general single-intake safety guidance. A research protocol should not be copied simply because it appears in a paper. Higher amounts can increase unwanted effects without providing a useful additional benefit.
Keep the EU safety guidance in view
EFSA identifies single intakes up to 200 mg and daily intake up to 400 mg spread through the day as raising no general safety concern for healthy, non-pregnant adults. These are assessment levels, not intake targets or guarantees of individual tolerance. During pregnancy, the corresponding daily level is 200 mg from all sources.[14]
Even 100 mg near bedtime can affect sleep in some adults. Count coffee, tea, energy drinks, tablets and pre-workout products together.
Judge the whole day, not just the session
An evening workout may feel easier while the night's sleep becomes worse. Track whether the overall trade-off is worthwhile. A stimulant-free session can be the better fit when training is late or caffeine causes discomfort.
Timing depends partly on the form used; many studies use caffeine about an hour before exercise.[13] That observation does not establish a universal schedule. Usual intake, meal timing, sensitivity and sleep all affect the practical choice.
Make the total easy to understand
A clearly stated caffeine amount is easier to assess than a blend of stimulants with unclear quantities. For an illustrative example, a 160 mg energy drink and a 150 mg pre-workout taken together provide 310 mg before counting any coffee.
Avoid loose, highly concentrated caffeine powder: small measuring errors can become large doses. People with relevant medical conditions, medication interactions or marked sensitivity should discuss caffeine use individually.
Match the ingredient to the demands of the activity
Beta-alanine works through repeated use
Beta-alanine helps raise muscle carnosine, which contributes to buffering changes in acidity during intense exercise. Research commonly uses approximately 4–6 g daily for several weeks, with benefits most relevant to selected high-intensity efforts lasting around one to four minutes.[15]
This is a description of studied protocols, not a recommendation for every exerciser. A single pre-workout serving is not equivalent to weeks of consistent use.
Tingling is a recognised effect, often reduced by smaller divided servings or suitable sustained-release formulations. It does not demonstrate that a workout will improve. Persistent or unusual symptoms should not simply be attributed to the supplement.
Dietary nitrate has outcome-specific evidence
Nitrate, often supplied in studied beetroot products, can contribute to nitric oxide availability. A 2025 umbrella review found benefits for some performance outcomes, including time to exhaustion and muscular endurance, but not all outcomes; it also identified substantial limitations in the quality of the underlying reviews.[16]
A beetroot-coloured powder or a vague “nitric oxide booster” is not necessarily equivalent to a product with a measured nitrate content. The amount supplied and the exercise being tested both matter. Broad claims of better circulation do not by themselves prove better sport performance.
Sports foods can solve a simpler problem
A carbohydrate drink or gel may be useful when exercise is long or demanding enough that eating during activity is part of the plan. Electrolyte products can help deliver a planned amount of sodium and fluid. The Australian Institute of Sport classifies these as sports foods with specific uses.[17]
Water and ordinary meals may cover a short, comfortable session. Longer events, heat, high sweat losses or difficulty eating can require more planning. A sugar-free electrolyte tablet supplies very little fuel, while a carbohydrate gel is not automatically a complete hydration plan.
Trial unfamiliar products during suitable training, when you can assess digestion and practicality. A competition day is a poor time to discover that a new product is difficult to tolerate.
Meet the need and check the combined amount
Some needs deserve a dependable supplement plan
For a vegan diet, B12 supplementation is a central part of the German Nutrition Society's guidance.[18] A reliable source should be established before deficiency develops; there is no need to wait for symptoms to make the nutrient important.
Vitamin D and other nutrients may also need supplemental provision depending on intake, life stage, absorption and local guidance. A general article cannot infer those needs from tiredness, a restrictive diet label or a single advertisement.
Iron should answer a specific question
Iron deficiency can require treatment, but fatigue has many possible causes. Iron status needs appropriate assessment, and ferritin can be affected by inflammation. Excessive supplemental iron can cause adverse effects.[19] Choose a plan that addresses the cause as well as the intake, with follow-up suited to the situation.
Stacking products can quietly increase the dose
A multivitamin, a recovery drink and a separate “energy” supplement may contain the same nutrient. Add the amounts across products using the servings you actually take. Milligrams and micrograms are different units: 1 mg equals 1,000 µg.
Upper limits are ceilings, not goals
EFSA's adult tolerable upper intake level for vitamin B6 is 12 mg/day from food and supplements combined, based on concern about peripheral nerve damage.[20] Water solubility does not mean that unrestricted long-term intake is harmless.
For vitamin D, EFSA's adult upper level is 100 µg vitamin D equivalents per day from dietary sources, including supplements. For ordinary vitamin D2 or D3, 100 µg corresponds to 4,000 IU.[21] This is not a routine recommended dose.
For example, a hypothetical 10 mg B6 tablet plus 5 mg from a pre-workout already provides 15 mg before food is counted. The fact that each product has its own serving instructions does not make the combined intake suitable.
Clinical treatment may use a different supervised regimen. Keep prescribed treatment distinct from self-selected supplementation, and tell the clinician about all products you use.
A supplement that prevents a deficiency may have no noticeable immediate effect. Conversely, feeling more energetic after a stimulating blend does not establish that a vitamin deficiency has been corrected.
EU regulation and Lithuanian notification have a defined role
In the EU, food supplements are regulated as foods. Specific requirements cover their composition and labelling; a food-supplement label is not the same as authorisation of a medicine.[22] Lawful sale should not be read as proof that a product will improve your chosen performance outcome.
In Lithuania, VMVT evaluates notification documents and includes eligible products in the notified food-supplement list. Products must be included in that list to be supplied legally on the Lithuanian market.[23] Checking the exact product is useful; notification does not replace asking whether the proposed use is supported by evidence.
Read the serving, not only the front of the package
Find the ingredient amounts for the recommended daily portion. A “serving” might mean several capsules or scoops. Check allergens, warnings, storage instructions and the responsible business's details.
Compare the active ingredient with the study. “5 g blend” does not tell you how much creatine, caffeine or beta-alanine it contains. Likewise, the weight of fish oil is not the same as its combined EPA and DHA content, and the weight of a mineral compound is not necessarily the amount of the mineral.
Separate three kinds of number
A label's nutrient reference value provides a common reference for labelling. An individual's nutritional requirement concerns the person. A tolerable upper intake level addresses long-term safety. They answer different questions; a high percentage on the label is not a measure of extra benefit.
Instructions and health claims need to be read as a whole. A familiar ingredient name in small print does not establish that the amount, formulation or intended use matches the research advertised beside it.
Check what a certification actually covers
Research on an ingredient cannot verify the contents of a container on a shelf. Quality checks address a separate question: whether the product meets the standards being tested.
NSF Certified for Sport includes checks relevant to product contents, manufacturing and substances prohibited in sport.[24] Informed Sport tests certified product batches for banned substances and provides a way to search product and batch details.[25] These programmes are examples of verification tools, not proof that a supplement will work for you.
Verify the exact product
Use the certifier's own directory. Match the product name, formulation and other listed details; check the batch or lot where the scheme provides it. A brand may sell both certified and uncertified products, and formulations can differ between regions.
A logo shown in a marketplace photograph is less informative than a matching current listing. Keep the packaging and purchase details when traceability matters.
Understand the limits
Testing addresses specified substances and standards. It cannot guarantee that every possible contaminant is absent, that the product suits every medical condition, or that several products are safe together.
For athletes subject to anti-doping rules, contamination has consequences beyond ordinary product quality. The IOC identifies inadvertent ingestion of prohibited substances as a recognised supplement risk.[1] Discuss products with qualified support familiar with your sport's rules; certification can reduce risk but cannot make it zero.
“Natural,” “premium” and “professional strength” do not describe a consistent level of safety or effectiveness. Prefer enough information to make the product understandable.
A five-step process for a manageable routine
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State the purpose.
Name the need or outcome. Decide whether food, preparation, training or recovery could address it directly.
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Check the match with evidence.
Look at the ingredient, amount, population and duration studied. Separate a clinical treatment plan from an optional sports product.
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Review the complete product list.
Check duplicate ingredients, allergens, caffeine totals and relevant medical advice. Choose a product with understandable quantities and suitable quality checks.
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Fit it into ordinary life.
Use clear instructions and a routine you can follow. Introduce one optional product at a time so its effects are easier to interpret.
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Review the result and the burden.
Consider the intended benefit, side effects, cost and complexity. Keep necessary nutrient provision dependable; reconsider optional products that do not justify their place.
A busy breakfast
The problem is convenience and little protein. A suitable yoghurt, tofu-based meal or powder may solve it. The choice can follow taste, access and budget.
An evening workout
The pre-workout feels effective, but sleep becomes difficult. Review the caffeine amount and timing, and compare with a session without stimulants.
A consistent strength plan
Meals and training are established. Creatine may be an optional addition, assessed through comparable training records rather than an immediate scale change.
Choose monitoring that can guide a decision
A short record of product, amount, training and symptoms may be enough for an optional sports supplement. Blood tests belong to specific clinical questions; there is no universal laboratory panel that proves a supplement routine is optimal.
If a new product causes a concerning reaction, stop using it and seek appropriate advice. For an ongoing prescribed nutrient treatment, discuss changes with the clinician responsible for the plan.
Every added product also takes money and attention. Those resources may sometimes improve life more when spent on food you enjoy, a workable training environment or time for recovery.
Clear answers about everyday supplement use
Do I need protein powder to build muscle?
No. It is a convenient source of protein. It becomes useful when it helps meet a need that is difficult to cover with ordinary meals.
Is whey isolate suitable for a milk allergy?
No. Reducing lactose does not remove the milk proteins responsible for milk allergy. Choose an appropriate alternative with suitable allergen information.
Is a shake immediately after training essential?
No. The day's intake and surrounding meals matter more than meeting a narrow deadline. Use a shake when it makes nourishment easier.
Do I have to load creatine?
No. Consistent daily use can build stores gradually; loading is an optional way to increase them sooner.
Does creatine automatically harm the kidneys?
No. Research does not support that general claim. Existing kidney problems need individual advice, and creatinine results require context rather than assumptions.
Are BCAAs better than a complete protein?
They supply fewer essential amino acids. If the aim is adequate protein provision, consider a substantial protein food or suitable complete protein source first.
Does tingling mean my pre-workout is effective?
No. Beta-alanine-related tingling is a sensory effect. Performance benefit depends on an appropriate protocol and the activity being performed.
Is 400 mg of caffeine a recommended daily target?
No. It is part of EFSA's safety assessment for healthy adults. Sensitivity and sleep may make a substantially lower intake more suitable.
Does certification guarantee a supplement will work?
No. Certification checks specified aspects of product quality. Effectiveness still depends on evidence for the ingredient, amount and intended use.
Should everyone take a multivitamin?
There is no universal need for the same supplement routine. Base nutrient provision on diet and individual requirements, and check overlaps with other products.
Sources and the scope of the guidance
Evidence and guidance checked: 5 September 2026. Sources include human studies, research reviews, professional guidance, EU authorities and the organisations responsible for the certification programmes described.
Study results are interpreted within their populations and outcomes. Older papers are used where they explain established composition or foundational protocols; newer evidence informs the relevant qualifications. Product examples and price calculations are illustrative, with no brand endorsement.
General adult guidance cannot replace a plan for a diagnosed deficiency, medical condition or other individual requirement.
- Maughan RJ, Burke LM, Dvorak J, et al. IOC consensus statement: dietary supplements and the high-performance athlete. British Journal of Sports Medicine. 2018;52(7):439–455. DOI: 10.1136/bjsports-2018-099027.Professional consensus on nutritional assessment, specific uses and risks in sport. Elite-sport guidance is not a universal supplement prescription. Return to text ↑
- Jäger R, Kerksick CM, Campbell BI, et al. ISSN position stand: protein and exercise. Journal of the International Society of Sports Nutrition. 2017;14:20. DOI: 10.1186/s12970-017-0177-8.Title shortened. Sports-nutrition guidance on total protein intake and distribution; individual clinical needs can differ. Return to text ↑
- Morton RW, Murphy KT, McKellar SR, et al. Protein supplementation and resistance-training gains: systematic review and meta-regression. British Journal of Sports Medicine. 2018;52(6):376–384. DOI: 10.1136/bjsports-2017-097608.Title abbreviated. Analysis of 49 studies; the modelled intake breakpoint describes average study data, not an exact individual requirement or ceiling. Return to text ↑
- Hoffman JR, Falvo MJ. Protein—Which is Best?. Journal of Sports Science and Medicine. 2004;3(3):118–130.Cited for established differences among protein ingredients and processing. Finished-product composition must be checked on its label. Return to text ↑
- National Institute of Diabetes and Digestive and Kidney Diseases. Definition & Facts for Lactose Intolerance. Official patient guidance; accessed September 2026.Explains the distinction between difficulty digesting lactose and an immune response to milk proteins. Return to text ↑
- Hevia-Larraín V, Gualano B, Longobardi I, et al. High-Protein Plant-Based Diet Versus a Protein-Matched Omnivorous Diet to Support Resistance Training Adaptations. Sports Medicine. 2021;51:1317–1330. DOI: 10.1007/s40279-021-01434-9.Title shortened. Twelve-week training study with protein matched using soy or whey. Habitual vegan and omnivorous groups were not randomly assigned their diets. Return to text ↑
- Oikawa SY, Kamal MJ, Webb EK, et al. Whey versus collagen peptides and muscle protein synthesis in older women. American Journal of Clinical Nutrition. 2020;111(3):708–718. DOI: 10.1093/ajcn/nqz332.Title abbreviated. Short randomised study measuring muscle protein synthesis, not long-term hypertrophy or every possible application of collagen. Return to text ↑
- Kreider RB, Kalman DS, Antonio J, et al. ISSN position stand: safety and efficacy of creatine supplementation. Journal of the International Society of Sports Nutrition. 2017;14:18. DOI: 10.1186/s12970-017-0173-z.Title shortened. Evidence for monohydrate, muscle stores, training outcomes and commonly studied supplementation protocols. Return to text ↑
- Antonio J, Candow DG, Forbes SC, et al. Common questions and misconceptions about creatine supplementation. Journal of the International Society of Sports Nutrition. 2021;18:13. DOI: 10.1186/s12970-021-00412-w.Title shortened. Review of creatine forms, water changes and common safety claims, including dehydration and cramping. Return to text ↑
- Elham Kabiri Naeini et al. Effect of creatine supplementation on kidney function: a systematic review and meta-analysis. BMC Nephrology. 2025;26:622. DOI: 10.1186/s12882-025-04558-6.Findings distinguish changes in creatinine from evidence of impaired filtration. They do not remove the need to assess abnormal tests or existing kidney disease. Return to text ↑
- Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?. Journal of the International Society of Sports Nutrition. 2017;14:30. DOI: 10.1186/s12970-017-0184-9.Cited for amino-acid requirements and the limits of signalling alone. Its historical review of oral trials is supplemented here by the Jackman study. Return to text ↑
- Jackman SR, Witard OC, Philp A, et al. Branched-chain amino acid ingestion and muscle protein synthesis following resistance exercise. Frontiers in Physiology. 2017;8:390. DOI: 10.3389/fphys.2017.00390.Title abbreviated. Small acute placebo-controlled study in trained men. It did not measure long-term growth or directly compare BCAAs with whey. Return to text ↑
- Guest NS, VanDusseldorp TA, Nelson MT, et al. ISSN position stand: caffeine and exercise performance. Journal of the International Society of Sports Nutrition. 2021;18:1. DOI: 10.1186/s12970-020-00383-4.Title shortened. Review of performance, timing and individual response. Research dosing and population safety guidance are different questions. Return to text ↑
- European Food Safety Authority. Caffeine. Safety guidance based on the 2015 scientific opinion; accessed September 2026.Assesses intake from all sources and effects on sleep. Assessment levels are not recommended targets or guarantees of individual tolerance. Return to text ↑
- Trexler ET, Smith-Ryan AE, Stout JR, et al. ISSN position stand: beta-alanine. Journal of the International Society of Sports Nutrition. 2015;12:30. DOI: 10.1186/s12970-015-0090-y.Title shortened. Describes repeated-use protocols, relevant exercise tasks and tingling. It does not establish a benefit from any single pre-workout serving. Return to text ↑
- Poon ETC, Iu JCK, Sum WMK, et al. Dietary nitrate supplementation and exercise performance: an umbrella review. Sports Medicine. 2025;55:1213–1231. DOI: 10.1007/s40279-025-02194-6.Title shortened. Synthesis of 20 systematic reviews found benefits for some outcomes and substantial methodological limitations. Return to text ↑
- Australian Institute of Sport, Australian Sports Commission. Group A: sports foods and supplements. Sports-nutrition framework; accessed September 2026.Evidence classifications refer to specific situations and protocols, including appropriate uses of sports drinks and gels. Return to text ↑
- German Nutrition Society (DGE). Update of the DGE position on vegan diet. Ernährungs Umschau International. 2024;71(7):60–84.Specifies B12 supplementation as part of an adequately planned vegan diet. Return to text ↑
- National Institutes of Health, Office of Dietary Supplements. Iron: Fact Sheet for Health Professionals. Official nutrient guidance; accessed September 2026.Discusses assessment, deficiency, interpretation of ferritin and adverse effects of excessive supplemental iron. Return to text ↑
- EFSA Panel on Nutrition, Novel Foods and Food Allergens. Scientific opinion on the tolerable upper intake level for vitamin B6. EFSA Journal. 2023;21(5):8006. DOI: 10.2903/j.efsa.2023.8006.Establishes an adult upper level of 12 mg/day from food and supplements combined, addressing peripheral neuropathy risk. Return to text ↑
- EFSA Panel on Nutrition, Novel Foods and Food Allergens. Scientific opinion on the tolerable upper intake level for vitamin D. EFSA Journal. 2023;21(8):8145. DOI: 10.2903/j.efsa.2023.8145.Title shortened. Adult upper level expressed in vitamin D equivalents; an upper level is not a routine recommended supplement dose. Return to text ↑
- European Food Safety Authority. Food supplements. EU regulatory overview; accessed September 2026.Explains food-supplement classification, ingredient assessment and specific labelling requirements. Return to text ↑
- Lithuanian State Food and Veterinary Service (VMVT). Maisto papildų notifikavimas—administracinė paslauga. Official notification procedure; accessed September 2026.Lithuanian-language guidance on document assessment and inclusion in the notified food-supplement list for the Lithuanian market. Return to text ↑
- NSF. Certified for Sport Program. Certification programme information; accessed September 2026.Primary source for this certifier's checks and product directory. Certification is not evidence of clinical or performance benefit. Return to text ↑
- Informed Sport. Athletes: supplement certification and batch verification. Certification programme information; accessed September 2026.Page title expanded for clarity. Describes batch testing and searching by product, formulation, region and lot details. Return to text ↑