How long before bed should you stop pre-workout?

As a working rule, take your last caffeine at least 8–10 hours before you want to sleep. That is our editorial rule of thumb based on caffeine's half-life of about five hours. The ISSN advises avoiding late-day doses, and sensitive people need a longer gap.

How long does caffeine stay in your body?

Half-life is the time for the blood level to fall by half. With a half-life of about five hours (it varies from person to person), caffeine decays like this:

So a 300 mg scoop at 17:00 still leaves about 150 mg at 22:00 and 75 mg at 03:00. Even a smaller residual can lighten sleep for sensitive people, even if you fall asleep fine.

What are the signs it is hurting your sleep?

• You need longer to fall asleep.
• You wake in the night or too early.
• You feel unrefreshed, with heavier morning fatigue.
• Resting heart rate is higher than usual.
• You rely on more caffeine the next day, which sets up a cycle.

What are the published caffeine amounts?

As of October 2026: Biogen Premium and USN XTS Hyperdrive 150 mg; Cellucor C4 200 mg (US page); USN Qhush Platinum Black 300 mg (global page). Many local tubs publish nothing, so treat unknown products as high. See how much caffeine is in pre-workout.

What if you only train in the evening?

1. Go stimulant-free. USN Qhush Hyperdrive Caffeine Free (R309.95–R349.99, October 2026), or take citrulline malate on its own. Citrulline has no stimulant effect.
2. Reduce caffeine. Use half a scoop of a 150 mg tub (75 mg) and see how you sleep.
3. Use caffeine earlier in the day if you have a late session, such as morning coffee, and nothing before the workout.
4. Move the session earlier if you can. Training itself can raise alertness for a while.

ATP Fitness Citrulline Malate (R280 for 250 g, R6.72 per 6 g) is a stimulant-free, sweetener-free way to take a pump ingredient in the evening; My Whey's (R4.78 per 6 g) is cheaper. Both have emerging, not strong, evidence for performance, and ATP publishes no sport certification.

How can you protect sleep?

• Keep a fixed caffeine cut-off time and put it on your phone.
• Count coffee, tea, cola, energy drinks and chocolate as well.
• Avoid alcohol close to bed; it fragments sleep.
• Keep your room cool, dark and quiet, which is harder in a hot Highveld or Durban summer, so consider a fan.
• Aim for seven to nine hours as an adult; teenagers need more, and should not use pre-workout.

Who should be extra careful?

Pregnant women (200 mg a day cap), people with anxiety or insomnia, and people on certain antidepressants or stimulants may clear or react to caffeine differently. Speak to a doctor if sleep problems persist. See is pre-workout safe and when to take pre-workout. Compare options at best pre-workout in South Africa.

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