What the label says, not advice for you
PT-141 Dosage and Half-Life From the Label
One amount appears on the label for its one approved group. You can read what researchers used and how many hours it stayed in your body.
The Label Lists One Amount for One Approved Group
The PT-141 label lists 1.75 mg for women with approved distressing low desire. The shot goes just under the skin. Its timing line begins at least 45 minutes before sexual activity [6]. Then there are strict limits on how often you can repeat it.
The label allows one shot within 24 hours. It sets another cap of eight in a month. Those are what the label allows, not instructions for you. A doctor has to decide whether a patient fits the approved use.
About 2.7 hours after a shot, half the drug is still in the body. One scan study found higher desire through 24 hours. You can't treat those times as the same thing. Your blood level can fall while a brain effect lasts longer.
PT-141 Dosage on the Label Is Exact
The PT-141 dosage on the label is 1.75 mg. On the label, the shot goes under the skin, only when the woman wants it [6]. It's timed at least 45 minutes before sexual activity, and the label allows one shot per 24 hours and 8 shots per month [6].
The label covers only its approved group. It isn't your own plan. You can't turn the trial amount into your dose. A doctor and patient make any choice about the approved drug.
Earlier work, called Phase 2, tested 0.75, 1.25, and 1.75 mg [6]. That means an early test. Researchers chose 1.75 mg for later trials. Women used shots in the thigh or belly. Lab material called PT-141 isn't the finished drug FDA approved.
PT-141 Dosage for Women Stayed the Same Across Main Trials
The label amount for women in the main trials was 1.75 mg. Women used the under-skin shot only when needed [6]. Use was capped at once per 24 hours. It was also capped at 8 times per month.
The two main trials followed 1267 women [3]. A 52-week follow-up included 684 women [4]. Both used the same plan. The women had distressing low desire and hadn't reached menopause.
You can use those counts to see who was studied. They don't give you or your doctor a personal plan. The approval doesn't extend to men or other uses.
PT-141 Half-Life Means Time for Half to Leave
PT-141 half-life is how long it takes your body to clear half of a shot. The label gives about 2.7 hours. Across people it ran 1.9-4.0 hours [6]. An older nose-spray study found 1.85-2.09 hours [6].
The highest blood level came around 0.5-1.0 hours [6]. That time can't tell you what strength you'd feel.
The label says about 21% of the drug, roughly one part in five, rides on proteins in the blood [6]. That's a detail for doctors, not a sign of whether it will do you any good. You pass most of it in urine, and a smaller share in stool [6].
The drug is a short chain folded into a ring, and the ring slows its breakdown [1]. None of this predicts your own response.
How Long PT-141 Can Affect Desire
The drug and its reported effect follow different clocks. Half the drug was gone in about 2.7 hours. The range was 1.9-4.0 hours [6]. The blood level peaked around 0.5-1.0 hours after the shot.
In one brain-scan study, PT-141 changed brain activity. Desire stayed higher through 24 hours [5]. Blood levels didn't stay high that long. The study can't tell you what one woman felt all day.
The label's 45-minute timing reflects a fairly quick start [6]. It can't predict how long any effect will last for you. The PT-141 half-life is only one part of timing. Think of blood level and felt effect as two clocks.