Updated On: 10 Sep 2026
The growing popularity of gym supplements has raised concerns over their potential health risks, with a neurosurgeon highlighting the case of a 22-year-old man who suffered a brain haemorrhage after regularly consuming a high-caffeine pre-workout supplement.
The supplement industry has expanded rapidly in recent years, with products marketed to improve energy, focus and athletic performance. While some supplements have legitimate benefits, experts warn that others may contain excessive stimulants, undisclosed ingredients or adulterated substances.
Neurosurgeon Dr Dhrumitsingh Rao shared the case in an Instagram post, saying the 22-year-old had consumed two scoops of pre-workout six days a week for 18 months.
One morning, the man experienced a pounding heartbeat and pain behind his right eye before beginning his workout. His left arm subsequently stopped responding. When he was examined, his blood pressure was recorded at 210/130 mmHg. A scan revealed a deep brain bleed, a condition known as hypertensive intracerebral haemorrhage.
What happened?
According to Dr Rao, the man was fit, had no family history of the condition and no known heart problem. His pre-workout contained 300 mg of caffeine, which he consumed on an empty stomach and had continued taking for 18 months.
The doctor said the stimulants triggered a hypertensive crisis, causing his blood pressure to rise to levels his brain vessels could not withstand. A cerebral blood vessel ruptured, resulting in a stroke. The man survived surgery but continues to recover movement in his left hand.
How stimulants can cause a crisis
Dr Rao explained the possible mechanism as a chain reaction: high doses of stimulants such as caffeine, synephrine and DMAA can trigger a surge in catecholamines, leading to an acute hypertensive crisis and potentially causing a cerebral blood vessel to rupture.
Pre-workout supplements are generally taken about 30 minutes before exercise to temporarily increase energy, focus and performance. However, Dr Rao warned that many products contain high amounts of caffeine and other stimulants.
Some formulations can contain caffeine equivalent to three or four espressos in a single scoop, while others may include stimulants such as synephrine, DMAA or yohimbine. He cautioned that such combinations could pose risks, particularly for people with an undiagnosed vascular abnormality or other underlying vulnerabilities.
The doctor stressed that his warning was not against exercising, but urged people to understand what they are consuming.
How to choose a pre-workout
- Check for third-party testing: Choose supplements tested by independent organisations to verify their ingredients and screen for banned substances or heavy metals.
- Avoid proprietary blends: Products labelled “Proprietary Blend”, “Performance Matrix” or “Pump Blend” without listing individual quantities can make it difficult to determine how much caffeine or other stimulants are being consumed. Consumers should look for products that clearly state every ingredient and its exact amount.
- Match ingredients to your goals: Different ingredients are intended for different types of training. Choose a formulation appropriate for your fitness goals and level of exercise.
- Manage stimulant intake: Caffeine can improve exercise performance, but excessive consumption may cause palpitations, anxiety and insomnia. The report suggests that 150-250 mg may be sufficient for a standard pre-workout and advises starting with half a serving of a mild formulation to assess tolerance.
Do you really need a pre-workout?
A pre-workout supplement is not essential for health or fitness. While ingredients such as caffeine and creatine have established performance benefits, a balanced meal, adequate hydration and sufficient sleep remain the foundation of effective training.
Pre-workouts do not directly burn fat or build muscle; they primarily provide an energy boost that may help people train harder.
People, particularly those with high blood pressure, heart conditions or sensitivity to stimulants, should consult a doctor before taking such supplements.
