Pre workout supplements are generally safe when used as directed, but they can cause side effects — especially for first-time users. Understanding what is normal, what is concerning, and how to minimise discomfort will help you get the most from your supplementation.

Common Side Effects

Beta-Alanine Tingles

The tingling or prickling sensation (paraesthesia) caused by beta-alanine is completely harmless. It typically affects the face, hands, and ears, lasting 15-30 minutes. It is not an allergic reaction and does not indicate any health concern. If you find it unpleasant, choose products without beta-alanine or with lower doses.

Caffeine Jitters

Excessive caffeine can cause jitteriness, anxiety, rapid heartbeat, and difficulty concentrating. This usually occurs when the dose exceeds your personal tolerance. Start with half a scoop of any new product to assess your response. See our caffeine guide for dosing advice.

Digestive Issues

Some users experience nausea, bloating, or stomach cramps, particularly with concentrated formulas or when taken on an empty stomach. Drinking plenty of water (400-500ml) with your pre workout and eating a small snack 30 minutes beforehand can help.

Serious Side Effects to Watch For

Elevated Heart Rate

If your resting heart rate exceeds 100 BPM after taking pre workout, or you experience chest pain, dizziness, or shortness of breath at rest, stop exercising and seek medical attention. These symptoms are rare but can indicate excessive stimulant sensitivity.

How to Minimise Side Effects

Starting with Half a Dose

We cannot stress this enough: always start with half a scoop of any new pre workout. This lets you assess your tolerance to the specific formula before committing to a full serving. You can increase gradually over subsequent sessions.

Staying Hydrated

Caffeine is a mild diuretic, and ingredients like glycerol and creatine draw water into muscles. Drink at least 500ml of water with your pre workout and maintain hydration throughout your session. Dehydration amplifies virtually every side effect.

Who Should Avoid Pre Workout?

Consult a doctor before using pre workout if you have heart conditions, high blood pressure, anxiety disorders, are pregnant or breastfeeding, are under 18, or take medications that interact with caffeine. If in doubt, our beginner pre workout guide recommends the safest starting options.