Health, fitness and the supplement aisle. An independent South African desk.
Pre-workout · Answer
No. We do not recommend pre-workout for anyone under 18. Tubs that publish a figure list about 150–300 mg of caffeine a scoop, which can reach or pass the limit EFSA used for adolescents (3 mg/kg of body weight) in a single scoop. Contamination risk and anti-doping rules in school sport add to the case. Food, sleep and a doctor or dietitian's advice come first.
We advise against it. Caffeine and stimulant-heavy products are not recommended for under-18s, the evidence on teenagers is thin, and the downside is sleep loss, anxiety and a fast heart rate in people who are still developing. This applies to schoolboy rugby, hockey, gym-going teens and everyone else. If a teenager is serious about performance, the first step is a conversation with a doctor or registered dietitian.
EFSA based its guidance for children and adolescents on 3 mg of caffeine per kg of body weight. For a 50 kg teenager that is about 150 mg for the whole day, before any cola, energy drink, coffee or chocolate.
| Teen weight | 3 mg/kg of caffeine | Caffeine in one Biogen Premium scoop (150 mg) |
|---|---|---|
| 50 kg | 150 mg | uses the whole allowance |
| 60 kg | 180 mg | uses 83% |
| 70 kg | 210 mg | uses 71% |
Published caffeine for pre-workouts sold in SA runs from 150 mg to 300 mg a scoop (the higher figures from US or global brand pages), and several brands do not publish it. Teenagers may not understand how all their caffeine adds up, particularly with energy drinks (see energy drink regulation for children).
Beta-alanine has limited data in under-18s and is best avoided. Citrulline, BCAAs, glutamine and the many botanical extracts in blends have no safety track record in teenagers. Proprietary blends hide the doses. We would not give any of them to a minor without professional advice.
Anti-doping rules apply strict liability, and school rugby has a documented problem. SAIDS reported steroid positives at Craven Week every year from 2014 to 2018, including 6 from 122 tests in 2018, and cases have continued into 2026. A Dutch study found 38% of 66 muscle, energy and fat-loss supplements contained undeclared doping substances. SAIDS flags muscle-building and energy products as the highest-risk category. For teen athletes, a contaminated tub can end a career, so see supplements for schoolboy sport.
Look at what is in the gym bag. Read labels, ask who is recommending the product, and keep a written record of anything a school-level player takes. Do not buy from unknown sellers or social-media shops. If a teen is already using pre-workout and feels unwell, stop and see a doctor.
Chest pain, fainting, a racing or irregular heartbeat that does not settle, seizures or severe agitation need emergency care. Call 10177 or 112.
Read the full parent guide: supplements under 18, what parents should know.
Educational information, not medical advice. Speak to a doctor, pharmacist or registered dietitian before using supplements if you are pregnant or breastfeeding, under 18, taking medication, or living with kidney, liver or heart disease. Prices were observed in October 2026 and are not offers.