Hardcore MYO TKO

Vitamin C (ascorbic acid)

Vitamin C is a water-soluble vitamin needed for collagen formation, immune function and iron absorption. EFSA set population reference intakes of 110 mg a day for men and 95 mg a day for women².

Beta-alanine

Beta-alanine is an amino acid that combines with histidine in muscle to form carnosine, which helps buffer acid during intense exercise³.

Agmatine sulfate

Agmatine is formed in the body from the amino acid arginine and acts as a signalling molecule in the nervous system. It is sold as agmatine sulfate in sports and nootropic products.

Higenamine

Higenamine is a plant alkaloid that stimulates β2-adrenergic receptors, the same receptor family targeted by asthma bronchodilators. It is found in plants such as Nandina domestica⁴.

Caffeine

Caffeine is a stimulant that blocks adenosine receptors in the brain, reducing perceived effort and fatigue. It is found in coffee, tea and energy drinks and is a common ingredient in pre-workout products⁵.

Dicaffeine malate (sold as Infinergy®) is caffeine bonded to malic acid. Its caffeine adds to the total caffeine in a product, but labels do not always state the caffeine equivalent.

DMAA (1,3-dimethylamylamine)

DMAA (1,3-dimethylamylamine, methylhexanamine) is a synthetic stimulant that constricts blood vessels and raises blood pressure. It has been sold in pre-workout and weight-loss supplements and as a recreational stimulant⁶.

L-citrulline and citrulline malate

L-citrulline is an amino acid that the body converts to arginine, a precursor of nitric oxide, which widens blood vessels. Citrulline malate combines citrulline with malic acid⁷.

Niacin (vitamin B3: nicotinic acid, niacinamide)

Niacin (vitamin B3) is used to make the coenzymes NAD and NADP, which are central to energy metabolism. It exists as nicotinic acid and nicotinamide (niacinamide)⁸.

L-tyrosine

L-tyrosine is an amino acid that the body uses to make the neurotransmitters dopamine and noradrenaline. It is found in protein-rich foods; N-acetyl-L-tyrosine is a related form⁹.

Ostarine (MK-2866, enobosarm)

Ostarine (also called MK-2866, GTx-024 or enobosarm) is a selective androgen receptor modulator developed as an investigational drug for muscle wasting¹⁰. OTR-AC is marketed as an acetylated (ester) form of ostarine; no human research on it has been published.

Yohimbine (yohimbe bark, rauwolscine)

Yohimbine is an alkaloid from the bark of the African tree Pausinystalia yohimbe. It blocks α2-adrenergic receptors, which increases noradrenaline release. Rauwolscine (alpha-yohimbine) is a closely related alkaloid.

Vitamin C (ascorbic acid)

Authorised EU claims include that vitamin C contributes to normal collagen formation, normal immune function, the reduction of tiredness and fatigue, and increased iron absorption¹¹.

Beta-alanine

The International Society of Sports Nutrition concludes that 4–6 g a day for at least 2–4 weeks raises muscle carnosine and improves performance in exercise lasting about 1–4 minutes³.

A meta-analysis found a significant overall ergogenic effect, with the size of the benefit depending on the type and duration of exercise¹².

Agmatine sulfate

Controlled human research on agmatine for exercise performance is very limited. Published human data are mostly small studies and a long-term case report¹³.

Higenamine

There are no controlled human trials showing that higenamine improves exercise performance or weight loss. Analyses of US supplements found up to about 62 mg per serving, with labels that often did not state the amount⁴.

Caffeine

The International Society of Sports Nutrition concludes that caffeine consistently improves exercise performance when consumed in doses of about 3–6 mg per kg of body mass, with benefits for muscular endurance, movement velocity, strength, sprinting, jumping and aerobic exercise⁵.

DMAA (1,3-dimethylamylamine)

No controlled trials show that DMAA improves athletic performance or weight loss. A pharmacokinetic study of a single 25 mg dose did not find meaningful changes in resting heart rate, blood pressure or body temperature¹⁴.

L-citrulline and citrulline malate

A review of human studies found that citrulline supplementation raises plasma arginine, and that several studies report improved exercise performance or recovery, but the results are inconsistent⁷.

Niacin (vitamin B3: nicotinic acid, niacinamide)

Authorised EU claims include that niacin contributes to normal energy-yielding metabolism, the reduction of tiredness and fatigue, and the maintenance of normal skin¹¹.

L-tyrosine

A review found that tyrosine may support cognitive performance in short-term stressful or cognitively demanding situations, when these neurotransmitters are temporarily depleted, but found no consistent effect on physical exercise performance⁹.

Ostarine (MK-2866, enobosarm)

A phase 2 trial in healthy older men and postmenopausal women found a dose-dependent increase in lean body mass and physical function over 12 weeks¹⁰. A phase 2 trial in people with cancer reported improved lean body mass¹⁵. These are clinical-development studies in specific patient groups, not studies of sports or bodybuilding use.

Yohimbine (yohimbe bark, rauwolscine)

A small trial in professional soccer players found reduced body fat with yohimbine but no change in body mass, muscle mass or performance¹⁶. Larger, independent trials are lacking.

Vitamin C (ascorbic acid)

Intakes above needs are largely excreted; extra benefit from high doses is not established.

Beta-alanine

Effects on strength and on endurance exercise beyond about 25 minutes are not established³. A single serving taken before training does not reproduce the daily supplementation used in research.

Agmatine sulfate

There are no large randomised trials showing a performance benefit from agmatine in healthy people. Claims of better "pump" or focus are not established.

Higenamine

Published research concerns supplement analysis rather than effects in humans⁴.

Caffeine

Responses vary widely between people, partly because of genetics and habitual caffeine use. Many studies use pure caffeine, so results do not automatically apply to multi-ingredient products⁵.

DMAA (1,3-dimethylamylamine)

The single-dose study does not reflect repeated use, higher doses or combination with other stimulants and exercise¹⁴. Analyses of sports and weight-loss supplements have repeatedly found stimulants that were not declared, or quantities different from the label¹⁷¹⁸.

L-citrulline and citrulline malate

Studies differ in dose, form (citrulline or citrulline malate, often with an unverified ratio) and exercise test, and many are small. The mechanism behind any performance effect is not established⁷.

Niacin (vitamin B3: nicotinic acid, niacinamide)

Benefits of intakes well above needs are not established in people who are not deficient.

L-tyrosine

Most studies are small and use single doses in laboratory settings⁹.

Ostarine (MK-2866, enobosarm)

Phase 2 results do not establish efficacy or long-term safety, and the compound has not been approved as a medicine. Analyses of products sold online as SARMs found that many did not contain the substance or amount stated on the label, and some contained other unapproved drugs¹⁹.

Yohimbine (yohimbe bark, rauwolscine)

Evidence for fat loss or performance is limited to small studies. Supplement labels are often inaccurate: of 49 US yohimbine supplements tested, only 2 gave accurate information on both the quantity and the known adverse effects²⁰.

Vitamin C (ascorbic acid)

No tolerable upper intake level has been set; high doses can cause digestive upset. People with a history of kidney stones or iron overload should ask a doctor before taking high doses.

Beta-alanine

The only commonly reported side effect is paraesthesia, a harmless tingling of the skin that is more likely with larger single doses³.

Agmatine sulfate

A case report described 5 years of high daily agmatine intake without detected adverse effects¹³. One case report cannot establish safety for the wider population.

Higenamine

As a β2-agonist, higenamine may raise heart rate and cause palpitations, and its safety at supplement doses has not been established⁴.

Caffeine

EFSA concluded that single doses of up to 200 mg, and daily intakes of up to 400 mg from all sources, do not raise safety concerns for healthy adults. For pregnant and breastfeeding women, daily intakes up to 200 mg do not raise concerns for the foetus or infant¹.

Higher intakes can cause anxiety, sleep disturbance, raised heart rate and blood pressure, and digestive upset. Combining several caffeine sources (coffee, energy drinks, pre-workouts) raises total intake¹⁵.

DMAA (1,3-dimethylamylamine)

DMAA is a potent pressor agent. Cases of cerebral haemorrhage have been reported in adults after using DMAA⁶.

L-citrulline and citrulline malate

Citrulline is generally well tolerated in the doses studied. Digestive discomfort has been reported, and people taking blood-pressure or erectile-dysfunction medication should ask a doctor, because citrulline raises arginine and nitric oxide production⁷.

Niacin (vitamin B3: nicotinic acid, niacinamide)

The EU Scientific Committee on Food set separate upper levels: 10 mg a day for nicotinic acid, which causes flushing, and 900 mg a day for nicotinamide²¹. "Flush-free" products use nicotinamide or inositol hexanicotinate.

L-tyrosine

People taking MAO inhibitors or thyroid medication should not use tyrosine supplements without medical advice.

Ostarine (MK-2866, enobosarm)

A systematic review of SARM use by athletes reports liver toxicity, heart toxicity, tendon damage, suppression of natural testosterone and other androgenic effects²². A national case series linked SARMs and other bodybuilding products to drug-induced liver injury²³.

Yohimbine (yohimbe bark, rauwolscine)

A review of poison-centre cases found that adverse events with yohimbine products had more serious outcomes than average exposures, including rapid heart rate, anxiety, high blood pressure and agitation²⁴. People with heart conditions, high blood pressure, anxiety disorders or taking antidepressants should not use yohimbine.

Contains a selective androgen receptor modulator (SARM). SARMs are investigational substances that are not authorised as medicinal products or as food (including food supplements) in the EU and are on the World Anti-Doping Agency (WADA) Prohibited List. Contains 1,3-dimethylamylamine (DMAA), a synthetic stimulant that is not authorised as a novel food in the EU and is on the WADA Prohibited List. Contains higenamine and/or octopamine, which are on the WADA Prohibited List. Contains yohimbine. Isolated yohimbine is classified as a medicinal substance in several EU member states; its legal status depends on the country of sale. No dosing information for human use is provided.

Vitamin C (ascorbic acid)

It is a permitted nutrient in EU food supplements²⁵; authorised claims may only be used in their approved wording and when the product is at least a source of the nutrient¹¹.

Beta-alanine

Beta-alanine is used in EU food supplements under national rules. No health claim is authorised¹¹.

Agmatine sulfate

Agmatine sulfate is used in some EU food supplements under national rules. No health claim is authorised¹¹. Whether a product needs novel food authorisation depends on its history of use²⁶.

Higenamine

Higenamine is not an authorised food supplement ingredient in the EU²⁶ and is prohibited at all times by the World Anti-Doping Agency as a β2-agonist¹⁸²⁷.

Caffeine

Caffeine is permitted in EU foods and food supplements, subject to labelling rules. It is not on the World Anti-Doping Agency Prohibited List²⁷.

DMAA (1,3-dimethylamylamine)

DMAA is not authorised as food or as a food supplement ingredient in the EU²⁶ and is prohibited in competition by the World Anti-Doping Agency¹⁷²⁷.

L-citrulline and citrulline malate

L-citrulline is used in EU food supplements under national rules. No health claim for citrulline is authorised in the EU¹¹.

Niacin (vitamin B3: nicotinic acid, niacinamide)

It is a permitted nutrient in EU food supplements²⁵; authorised claims may only be used in their approved wording and when the product is at least a source of the nutrient¹¹.

L-tyrosine

Amino acids such as L-tyrosine are used in EU food supplements under national rules. No health claim is authorised¹¹.

Ostarine (MK-2866, enobosarm)

Ostarine is not an approved medicine and is not permitted in food or food supplements in the EU²⁸²⁶. SARMs have been on the World Anti-Doping Agency Prohibited List since 2008 and are prohibited at all times²⁹²⁷.

Yohimbine (yohimbe bark, rauwolscine)

Yohimbine is a pharmacologically active substance. Its use in food is regulated under Regulation (EC) No 1925/2006 and national rules³⁰, and several EU Member States treat it as a medicinal substance²⁸.