Nutrifitt Carnage pre-workout

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 products².

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.

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 acid³.

Beta-alanine

Beta-alanine is an amino acid that combines with histidine in muscle to form carnosine, which helps buffer acid during intense exercise⁴.

Betaine (trimethylglycine)

Betaine (trimethylglycine) occurs naturally in beetroot, spinach and wheat. It acts as an osmolyte and as a methyl donor in homocysteine metabolism.

Choline (choline bitartrate, alpha-GPC)

Choline is an essential nutrient used to make cell membranes and the neurotransmitter acetylcholine. EFSA set an adequate intake of 400 mg a day for adults⁵. Supplements supply it as choline bitartrate, alpha-GPC or citicoline.

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 form⁶.

Piperine (black pepper extract, BioPerine®)

Piperine is the pungent alkaloid of black pepper, added to supplements as a "bioavailability enhancer".

Synephrine (bitter orange, Citrus aurantium)

p-Synephrine is the main protoalkaloid of bitter orange (Citrus aurantium). It is structurally related to adrenaline and is used in weight-loss and pre-workout products⁷.

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.

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 exercise².

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 inconsistent³.

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 minutes⁴.

A meta-analysis found a significant overall ergogenic effect, with the size of the benefit depending on the type and duration of exercise⁸.

Betaine (trimethylglycine)

A meta-analysis found that betaine supplementation for at least 7 days improved muscular strength, especially lower-body strength, and may improve jumping performance⁹. The EU authorises a claim that betaine contributes to normal homocysteine metabolism at 1.5 g a day¹⁰.

Choline (choline bitartrate, alpha-GPC)

The EU authorises claims that choline contributes to normal lipid metabolism, homocysteine metabolism and liver function for foods that are a source of choline¹⁰. Claims that choline improves focus or exercise performance are not authorised.

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 performance⁶.

Piperine (black pepper extract, BioPerine®)

A 2026 review of 22 human pharmacokinetic studies found that reports of enhanced nutrient absorption come mainly from manufacturer-affiliated studies, and that independent trials did not confirm enhancement for curcumin or resveratrol at supplement doses¹¹.

Synephrine (bitter orange, Citrus aurantium)

A review of human clinical studies reported small increases in energy expenditure and modest weight loss with bitter orange extract or p-synephrine products over 6–12 weeks, many in combination with other ingredients⁷.

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 performance¹². Larger, independent trials are lacking.

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 products².

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 established³.

Beta-alanine

Effects on strength and on endurance exercise beyond about 25 minutes are not established⁴. A single serving taken before training does not reproduce the daily supplementation used in research.

Betaine (trimethylglycine)

The studies are small and differ in dose and duration⁹.

Choline (choline bitartrate, alpha-GPC)

Evidence on cognitive or performance effects in healthy adults is limited.

L-tyrosine

Most studies are small and use single doses in laboratory settings⁶.

Piperine (black pepper extract, BioPerine®)

Piperine raises blood levels of other compounds mainly by inhibiting drug-metabolising enzymes (CYP3A4, CYP2C9) and P-glycoprotein, not by improving absorption¹¹.

Synephrine (bitter orange, Citrus aurantium)

Most studies are small, short and use multi-ingredient products, and longer studies are needed to establish efficacy and safety⁷.

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 effects¹³.

• High-stimulant formula – for experienced users only.
• Do not exceed 1 serving per day.

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 intake¹².

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 production³.

Beta-alanine

The only commonly reported side effect is paraesthesia, a harmless tingling of the skin that is more likely with larger single doses⁴.

Betaine (trimethylglycine)

Betaine is generally well tolerated; high intakes may raise blood cholesterol in some people.

Choline (choline bitartrate, alpha-GPC)

High intakes can cause a fishy body odour, sweating and digestive upset.

L-tyrosine

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

Piperine (black pepper extract, BioPerine®)

Because it inhibits drug-metabolising enzymes, piperine can raise blood levels of prescription medicines, including drugs with a narrow therapeutic index. People taking medication should ask a pharmacist first¹¹.

Synephrine (bitter orange, Citrus aurantium)

The reviewed studies did not report serious adverse effects at the doses tested⁷, but combining synephrine with caffeine and other stimulants increases cardiovascular stress. People with high blood pressure, heart-rhythm disorders or taking stimulant or antidepressant medication should avoid it.

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 agitation¹⁴. People with heart conditions, high blood pressure, anxiety disorders or taking antidepressants should not use yohimbine.

Contains yohimbine and rauwolscine. Isolated yohimbine is classified as a medicinal substance in several EU member states; its legal status depends on the country of sale.

Caffeine

Caffeine is permitted in EU foods and food supplements, subject to labelling rules. It is not on the World Anti-Doping Agency Prohibited List¹⁵.

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 EU¹⁰.

Beta-alanine

Beta-alanine is used in EU food supplements under national rules. No health claim is authorised¹⁰.

Betaine (trimethylglycine)

Betaine is used in EU food supplements; the homocysteine claim may be used only in its authorised wording and conditions¹⁰.

Choline (choline bitartrate, alpha-GPC)

Choline is a permitted nutrient source in EU food supplements¹⁶¹⁰.

L-tyrosine

Amino acids such as L-tyrosine are used in EU food supplements under national rules. No health claim is authorised¹⁰.

Piperine (black pepper extract, BioPerine®)

No health claim for this ingredient is authorised in the EU¹⁰; botanical ingredients are sold under national food-supplement rules¹⁶.

Synephrine (bitter orange, Citrus aurantium)

Bitter orange extracts are used in EU food supplements under national rules, which differ between Member States¹⁶.

Yohimbine (yohimbe bark, rauwolscine)

Yohimbine is a pharmacologically active substance. Its use in food is regulated under Regulation (EC) No 1925/2006 and national rules¹⁷, and several EU Member States treat it as a medicinal substance¹⁸.