Pregnenolone half-life
Pregnenolone is a precursor steroid hormone, and its own time in the blood is short and poorly characterized in humans, with reported plasma half-life estimates on the order of 1 to 3 hours. It does not persist as the parent compound because the body rapidly converts it into a range of downstream steroids and their sulfate forms, several of which remain in circulation longer than pregnenolone itself. Because the parent clears quickly, oral doses are usually split across the day, and steady blood levels rely on repeated dosing rather than the compound accumulating on its own.
What a half-life actually means
A half-life is the time it takes for half of what is in your blood to be gone. It does not mean the compound is finished at that point. Half goes, then half of what is left goes, and so on.
That is why the last traces take so much longer to disappear than the first. Most references treat something as effectively cleared after about five half-lives, which for Pregnenolone is roughly 10 hours.
How Pregnenolone clears
| Half-lives | Time since dose | Roughly left |
|---|---|---|
| 1 | 2 hours | 50% |
| 2 | 4 hours | 25% |
| 3 | 6 hours | 12.5% |
| 4 | 8 hours | 6.25% |
| 5 | 10 hours | 3.125% |
These are round numbers from a single half-life figure. Real clearance shifts with dose, body composition, liver and kidney function, and what else you are taking. Treat it as a shape, not a schedule.
Why the timing matters
A short half-life means levels swing between doses, so timing and frequency do most of the work. A long half-life means levels build for days or weeks before they settle, so a change you make today might not show up for a while, and stopping does not clear things straight away.
Pregnenolone sits at about 2 hours, so it behaves like the short end of that range.
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On a repeating schedule the amount in your body climbs until what you take in each interval matches what clears in it. That plateau is called steady state, and it arrives after roughly five half-lives whatever the dose. For Pregnenolone that is about 10 hours of consistent dosing.
The typical starting schedule is 1x daily (AM), at 25 mg/day. Until that plateau, every dose lands on top of more of the last one than it will later, which is why the first weeks of a protocol can feel different from the same dose a month in.
Skipping doses resets part of that climb. One missed dose costs roughly one half-life of accumulation, so the shorter the half-life the more a gap matters.
Mixing and measuring Pregnenolone
Oral capsule — no reconstitution
Store at 15-25°C (room temp). 2 years sealed.