Taurine: morning or night?

Pick the slot that matches your goal. Evening 1 to 3 g taurine 30 to 60 minutes before bed supports calm and sleep onset. Pre-workout 1 to 2 g taurine 30 to 45 minutes before training supports endurance, hydration, and exercise performance. Both work; pick one. Some users split (1 g pre-workout and 1 to 2 g evening). There is no strong circadian benefit to morning taurine specifically.

Taurine is a sulfur-containing amino acid (technically an aminosulfonic acid) abundant in the heart, brain, retina, and muscle. The body makes some from cysteine and methionine, but plasma levels fall with age, illness, and vegan diets (taurine is found almost entirely in animal foods). Supplemental taurine has a half-life of roughly 1 hour and is largely cleared within 12 hours, so daily total matters more than slot. The most popular evening use is for its calming, GABA-modulating effect, which can help sleep onset and reduce evening anxiety. The pre-workout use takes advantage of its osmotic effect on muscle cells (cell volumisation and endurance) and its mild blood-flow benefit.

The windows above are anchored to a conventional day, not to clock time. If you work nights or wake at midday, shift the whole pattern rather than the individual dose: treat your own waking hour as "morning" and your own wind-down hour as "night". For Taurine the thing that matters is the relationship to your sleep and to your meals, not the number on the clock. Shift workers rotating between days and nights get the most consistent results by anchoring the dose to a fixed event, the first meal of a shift, rather than to a fixed time.

Take it later the same day if there is still a sensible slot left, with water at any point. If the day is gone, skip it and resume tomorrow. Do not double the next dose to compensate: for anything stored in the body a single miss is inconsequential, and for anything cleared quickly a double dose gives no benefit while raising the chance of side effects. Adherence over weeks matters far more than any single perfectly timed dose, which is why the best window for Taurine is usually the one you will actually keep.

• Evening

  1–3g for calm or sleep support

• Pre-workout

  1–2g 30–45 min before training

• How much taurine for sleep?+

  Most users find 1,000 to 3,000 mg taken 30 to 60 minutes before bed effective for calm and sleep onset. The evidence is preliminary but the tolerability is excellent. Pair with magnesium glycinate and glycine for a stronger evening stack. Higher doses (above 3,000 mg) do not improve sleep further and may cause GI loosening.
• Does it matter if I take Taurine at a different time each day?+

  Some variation is fine. A fixed slot is recommended mainly because it is the easiest way to not forget, and because it keeps levels of quickly cleared compounds steadier. Drifting an hour or two either side of your usual time changes very little. Drifting between morning and bedtime is worth avoiding, especially if Taurine affects your sleep or energy.
• Can I take Taurine twice a day instead?+

  Splitting a dose is often better tolerated and, for compounds the body clears quickly, keeps blood levels steadier than one large dose. Do not increase the total by splitting it: divide the daily amount you were already taking. Check the label, some products are formulated as a single daily dose and should not be split.

• EFSA. Scientific opinion on caffeine and taurine. 2009