How Long Does It Take Progesterone to Get Out of Your System?

Progesterone itself clears from your bloodstream faster than most people expect. When taken by mouth, the hormone’s blood levels peak within a couple of hours and drop back toward baseline within roughly a day, with a half-life somewhere between five and ten hours when measured with modern lab methods. But “how long it takes to leave your system” depends heavily on the formulation you’re using, because the same hormone delivered through a different route can behave very differently. A vaginal suppository, a skin cream, and an intramuscular injection each release progesterone on their own timeline, and the answer stretches from hours to weeks depending on which one you mean.

How Your Liver Handles Progesterone

Before getting into specific formulations, it helps to understand why progesterone disappears so fast once it’s in your blood. Your liver is extraordinarily efficient at breaking it down. In lab studies using human liver tissue, progesterone was cleared with a half-life of under three minutes, meaning the liver chews through it almost as quickly as it arrives.¹ The intestinal wall also contributes, though it works much more slowly, with a half-life measured in hours rather than minutes. This rapid liver breakdown is the main reason oral progesterone has such low bioavailability: much of the dose gets metabolized on its first pass through the liver before it ever reaches general circulation. It also explains why different delivery routes produce such different timelines. A formulation that bypasses the liver, even partially, can keep progesterone circulating longer.

Oral Progesterone

If you’re taking micronized progesterone capsules by mouth (the most common brand name is Prometrium), blood levels typically peak about two hours after you swallow a dose.² How quickly those levels fall has been a source of confusion, because older lab techniques gave misleadingly long estimates. Studies using immunoassays reported a half-life of 16 to 18 hours, but more precise methods have revised that down to about 5 to 10 hours, with meaningfully elevated progesterone levels lasting only around 4 to 8 hours after a single dose.³ In practical terms, most of the progesterone from a single oral dose is gone from your blood within 12 to 24 hours.

That surprisingly short window is why some doctors prescribe oral progesterone to be taken twice daily rather than once. When a 100 mg or 200 mg dose is taken twice a day, the metabolite levels stay elevated for at least 12 hours after each dose, which smooths out the peaks and valleys somewhat.² If you stop taking oral progesterone entirely, you can expect blood levels to fall to near baseline within about a day, and certainly within two days for the vast majority of people.

Vaginal Progesterone

Vaginal administration, whether as suppositories, gels (Crinone, Endometrin), or compounded preparations, follows a different curve. Peak blood levels arrive later, usually around four to eight hours after insertion rather than two hours.⁴⁵ The elimination half-life also varies by formulation: roughly 9 to 10 hours for some suppository types and closer to 14 hours for others.⁴

One reassuring finding is that vaginal progesterone does not seem to accumulate with repeated daily use. In a study of postmenopausal women given vaginal suppositories over six days, plasma levels actually drifted slightly downward rather than building up.⁴ So when you stop using vaginal progesterone, you’re generally looking at clearance within one to two days, similar to oral but shifted a bit later because of the slower absorption.

There’s an important quirk with vaginal delivery, though. Progesterone administered vaginally achieves high concentrations in uterine tissue that don’t always show up proportionally in blood tests, a phenomenon sometimes called the “first uterine pass effect.” Your blood level might look modest while the tissue that actually matters for, say, supporting an early pregnancy is getting a much larger dose. This means blood clearance times don’t fully capture how long the hormone is active at its target.

Transdermal Progesterone

Progesterone creams and gels applied to the skin follow yet another pattern. In studies of postmenopausal women using topical preparations, the half-life was dramatically longer than with oral or vaginal routes, ranging from about 30 to 40 hours.⁶ The trade-off is that peak blood levels are much lower (often only 1 to 2 ng/mL), so the overall exposure is modest. Still, the extended half-life means it takes roughly a week of not applying the cream before levels fully return to baseline. The skin and subcutaneous fat act as a slow-release reservoir, gradually feeding progesterone into the bloodstream long after you’ve stopped applying it.

This is worth knowing if you’re switching formulations or timing things around a fertility procedure. Transdermal progesterone hangs around longer than oral or vaginal forms, even though it never gets your blood levels as high.

Injectable Progesterone

Intramuscular progesterone in oil, commonly used in IVF protocols, produces high, sustained blood levels. In one study comparing oral and intramuscular progesterone during IVF, women receiving injections had progesterone levels around 76 to 78 ng/mL at both day 21 and day 28 of their cycles, showing minimal decline over the course of a week.⁷ The oil depot in the muscle releases progesterone gradually, keeping levels elevated much longer than a single oral or vaginal dose could manage.

After you stop the injections, the remaining oil depot continues to release progesterone for several days. Most clinicians estimate clearance takes about three to five days, though this varies with the injection site, the volume of oil used, and individual absorption rates. The decline isn’t a cliff; it’s more of a steady slope.

Depot Medroxyprogesterone Acetate (Depo-Provera)

This is where the timeline gets dramatically longer, but an important distinction is needed. Depo-Provera uses medroxyprogesterone acetate (MPA), a synthetic progestin, not bioidentical progesterone. It is engineered to persist in the body for months, which is the whole point of a quarterly contraceptive injection. If your question is about the Depo shot specifically, the clearance timeline is measured in months, not hours or days.

The median time for ovulation to return after a subcutaneous Depo-Provera injection is about 30 weeks (roughly seven months after the last shot), with virtually all women ovulating again within 12 months.⁸ The intramuscular version follows a similar timeline: the estimated median time from the last injection to ovulation is about six months, and some women take up to about 10 or 11 months.⁹ Large studies from Thailand found a median delay to conception of about nine months after the last injection, counting from the date of the shot rather than the date it “wears off.”¹⁰

The long clearance time isn’t because the drug is inherently hard to metabolize. It’s because the injection creates a physical reservoir of MPA crystals in the muscle or fat that dissolve slowly over many weeks. By around 12 months after the last injection, the cumulative ovulation return rate is above 95%, so permanent effects are not a concern.⁹

Why Clearance Varies From Person to Person

Even within the same formulation, some people clear progesterone faster than others. A study of women undergoing frozen embryo transfers identified several factors that correlated with how high (or low) their progesterone levels were the day before the procedure. Higher body weight was associated with lower progesterone concentrations, likely because a larger volume of distribution dilutes the drug. Age had a modest positive effect, meaning older women tended to have slightly higher levels for the same dose. Even the time of day that blood was drawn mattered: samples taken later in the day showed lower progesterone levels than morning samples.¹¹

The variation in blood levels after oral dosing is particularly striking. One comparison found that peak levels after a single oral dose ranged from 8.5 to 70.6 ng/mL across different women given the same formulation.⁵ That’s nearly a tenfold difference. Vaginal administration showed even wider variation, from 4.4 to 181.1 ng/mL. This means the “average” clearance time is only loosely predictive for any individual. If you absorb more of the dose, there’s more to clear. If your liver enzymes are particularly active, clearance is faster.

Metabolites Linger Longer Than the Hormone Itself

One thing that trips people up is the difference between progesterone itself and its metabolites. Your body doesn’t simply destroy progesterone; it converts it into a family of breakdown products, the most commonly measured being pregnanediol glucuronide (PDG), which is excreted in urine. PDG concentrations are roughly 1,000 to 4,000 times higher than urinary progesterone concentrations, and they peak considerably later, usually 4 to 12 hours after a dose compared to the 1-to-2-hour blood peak.¹²

After an intramuscular injection, both urinary progesterone and PDG remained elevated at 24 hours. After oral dosing, they peaked and then dropped, reaching levels 10 to 20 times lower by 24 hours.¹² If you’re tracking progesterone using urine-based tests (some fertility monitors do this), your readings will stay positive longer than blood tests would, because you’re measuring the slower metabolite rather than the parent hormone. This is worth remembering if you’re trying to confirm that progesterone has fully left your system.

What Progesterone Withdrawal Feels Like

When progesterone levels drop, whether because you stopped taking a supplement or because of the natural luteal-phase decline before your period, the effects aren’t limited to what’s happening in the uterus. Progesterone is converted in the brain into a neurosteroid called allopregnanolone, which enhances the activity of calming GABA receptors. When progesterone falls, allopregnanolone falls with it, and the brain’s inhibitory signaling temporarily weakens.

Animal studies have shown that progesterone withdrawal increases anxiety-like behavior and lowers the seizure threshold, effects comparable in magnitude to withdrawal from benzodiazepines.¹³ The mechanism involves a temporary upregulation of certain GABA receptor subtypes in the hippocampus, which paradoxically makes the brain more excitable rather than less.¹⁴ In humans, this dynamic likely contributes to the irritability, anxiety, insomnia, and mood shifts many women experience premenstrually or when discontinuing progesterone supplementation. The neurosteroid effects can persist for a day or two after progesterone blood levels have already bottomed out, because the receptor changes in the brain take time to normalize.

If you’ve been on a higher dose of progesterone for a longer period, the withdrawal effects tend to be more noticeable. Some clinicians taper progesterone rather than stopping abruptly, particularly in fertility treatment settings, partly for this reason and partly to avoid sudden drops in uterine support.

Stopping Progesterone During IVF and Early Pregnancy

For women using progesterone to support an IVF pregnancy, the question of when to stop is closely tied to clearance. The placenta gradually takes over progesterone production between about weeks 7 and 10 of pregnancy, so supplementation is typically continued until at least week 8 to 12. How quickly you stop matters less than you might think. In a study comparing early discontinuation of progesterone supplements (at the time of the first positive pregnancy test) to continuation through later weeks, there were no significant differences in clinical pregnancy rate, ongoing pregnancy rate, or live birth rate between the two groups.¹⁵

That finding suggests the placenta picks up the slack quickly enough that a sharp drop in exogenous progesterone isn’t catastrophic, at least in fresh embryo transfer cycles. It also means the clearance timeline of the particular formulation you’re using (a day or two for oral or vaginal, a few days for injectable) is unlikely to create a dangerous gap in progesterone support by the time you’re instructed to stop.

The Natural Postpartum Drop

After delivery, progesterone levels plunge dramatically in a matter of hours. During pregnancy, progesterone reaches extremely high concentrations, often above 100 ng/mL in the third trimester. Once the placenta is delivered, the source of that progesterone is physically removed, and blood levels crash to baseline within about 24 to 48 hours. This is among the most abrupt hormonal shifts in human physiology, and it likely contributes to the “baby blues” experienced by many women in the first postpartum week, operating through the same neurosteroid withdrawal mechanisms described above. Levels remain low until the first signs of returning ovarian cycles, which for women who are not breastfeeding is typically several weeks postpartum.

Formulation Clearance at a Glance

Because the differences are so route-dependent, here’s how the main formulations compare:

Oral capsules: Half-life of 5 to 10 hours; blood levels return to baseline within about a day of stopping.
Vaginal gels or suppositories: Half-life of 9 to 14 hours; clearance typically within one to two days.
Transdermal creams: Half-life of 30 to 40 hours; may take up to a week for full clearance due to skin and fat depot effects.
Intramuscular oil injections: Sustained levels for days after each injection; expect clearance within roughly three to five days after the last shot.
Depot medroxyprogesterone (Depo-Provera): A synthetic progestin, not bioidentical progesterone; ovulation returns at a median of six to seven months after the last injection, with nearly all women ovulating within 12 months.

These ranges assume typical metabolism. If you have liver disease, are taking medications that affect liver enzyme activity, or have an unusually high or low body weight, your personal clearance could sit at either end of the range. The wide individual variation in absorption, as documented by that nearly tenfold difference in peak levels among women taking the same oral dose, means blood testing is the only way to know for certain that progesterone has left your system.⁵