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FDA-approved pamoate depots · schedules depend on the use
Triptorelin
Triptorelin labels give separate uses and schedules for Trelstar and Triptodur. Their doses cannot be added or used to infer other schedules.
- Trelstar and Triptodur have different approved uses.
- The long-acting strengths are not additive.
- These labels do not set a schedule for IVF or other studied uses.
Triptorelin is a gonadotropin-releasing hormone agonist. FDA distinguishes triptorelin base, triptorelin pamoate and triptorelin acetate. The current US products found for people are Trelstar and Triptodur.
Both use the pamoate salt in a depot, which releases the drug over time.
The current Trelstar label covers advanced prostate cancer and lists three schedules for injections into a muscle. They are 3.75 mg every four weeks, 11.25 mg every 12 weeks, or 22.5 mg every 24 weeks. These long-acting products release the drug differently, so their strengths are not additive.
The current Triptodur label covers central precocious puberty in children age two years and older. Its schedule is 22.5 mg into a muscle every 24 weeks. Each pamoate schedule applies to its approved use.
Neither label sets a schedule for IVF, endometriosis, preserving ovarian function, optimizing hormones or using acetate products.
What matters first
- The product and approved use set the time between doses: Trelstar and Triptodur are pamoate depots for different patient groups. Even when their strengths or dose intervals match, one approved use does not apply to the other product.
- Trelstar strengths are not additive: The 3.75, 11.25 and 22.5 mg products release the drug differently. Each belongs to its intended four-, 12- or 24-week interval. They are not combined as multiples.
- Base, salt and mixing volume describe different things: Triptodur contains 22.5 mg triptorelin base in one vial, equal to 31 mg triptorelin pamoate. That vial is mixed with 2 mL sterile water. These are not separate doses, and the values cannot be added or divided to calculate a concentration for personal use.
- An early surge comes before hormone levels fall: The Trelstar label describes an early testosterone rise, followed by a sustained drop. These findings do not show that the drug is useful for general testosterone optimization.
- Human research does not expand the approved labels: One IVF protocol studied daily triptorelin acetate. A depot study omitted its strength. Other cancer studies tested uses outside the approved labels. Each remains a research setting.
- OvuGel is for animals: Its label gives 100 micrograms of triptorelin base per mL. The drug is present as triptorelin acetate. It describes a 2 mL amount placed in the vagina of weaned sows. This is not a human acetate strength, route, dose or approval.
Identity, salts, and names
FDA substance records distinguish triptorelin, UNII 9081Y98W2V from triptorelin pamoate, UNII 08AN7WA2G0 and triptorelin acetate, UNII 43OFW291R9. The FDA also lists embonate as a name for pamoate. A name record alone does not prove that a product is approved.
Trelstar and Triptodur are the current US human pamoate products found. Decapeptyl appears as a synonym for pamoate and in non-US or research trial records. A matching name does not prove that a US product exists. OvuGel contains the acetate salt but has an animal label.
Each source names a salt, product, use and route. Its strengths and gaps between doses belong to that product alone.
Trelstar for advanced prostate cancer
The current Trelstar FDA label lists triptorelin pamoate for advanced prostate cancer. It gives three schedules for one injection into a muscle: 3.75 mg every four weeks, 11.25 mg every 12 weeks, or 22.5 mg every 24 weeks. The label says these strengths release the drug differently and cannot be added together.
Each is used at its stated time between doses.
The label states strength as triptorelin base, while the active material is triptorelin pamoate. Each product contains freeze-dried microgranules that are mixed with 2 mL sterile water and given promptly as a suspension. The water is used to mix that product.
Its volume does not provide a way to work out a dose for personal use or to split the dose.
The label describes an early testosterone surge, followed by a sustained drop:
- The 11.25 mg trial randomized 346 men. It compared 11.25 mg every 12 weeks with 3.75 mg every 28 days. In the 11.25 mg group, 97.7% reached testosterone at or below 50 ng/dL at day 29. From day 57 through day 253, 94.4% maintained that level.
- The 22.5 mg trial had no control group. It enrolled 120 men who received two injections 24 weeks apart. At day 29, 97.5% had testosterone at or below 50 ng/dL. From day 57 through day 337, 93.3% maintained that level.
An original randomized active-control trial enrolled men with advanced prostate cancer. It assigned triptorelin 3.75 mg or leuprolide 7.5 mg into a muscle. The schedule was every 28 days for nine injections.
There were 284 treated men. At day 29, triptorelin reached the protocol’s castrate threshold less often. The rates were 91.2% versus 99.3%.
Mean and cumulative maintenance rates were equivalent from days 29–253. The study measured how well treatment lowered testosterone. That alone does not show a broader gain in function.
Triptodur for central precocious puberty
The current Triptodur FDA label lists triptorelin pamoate for central precocious puberty in children age two years and older. Its schedule is 22.5 mg as one injection into a muscle every 24 weeks.
The supporting study was open-label, with no control group. It followed 44 children age 2–9 years who had not been treated before: 39 girls and five boys. Follow-up covered two dosing intervals.
At each time point measured, at least 93% met the label’s prepubertal stimulated-LH threshold. Findings on sex steroids and clinical signs also came from this small group.
One vial contains 22.5 mg triptorelin, which the label states equals 31 mg triptorelin pamoate. It is mixed with 2 mL sterile water. The base amount, salt equivalent and water volume describe one product, not doses that can be added or swapped.
Other uses studied in people
IVF dose-finding study of triptorelin acetate
An IVF dose-finding trial randomized 240 women equally across four groups. These received placebo or triptorelin acetate 15, 50 or 100 micrograms daily. The long IVF protocol also used FSH for ovarian stimulation.
The checked abstract does not state the drug’s route.
Premature LH surge occurred in 23% of the placebo group and none of the triptorelin groups. The 50 and 100 microgram groups produced more oocytes and embryos. Dose had no relationship with implantation, pregnancy, ongoing pregnancy, live birth or baby take-home rates.
This result concerns hormone control in an IVF plan that used several drugs. It does not set a general fertility schedule. It also does not show that an acetate product is now approved for people.
Endometriosis study with an unstated depot strength
A placebo-controlled endometriosis trial included 49 women with symptoms. Laparoscopy had confirmed their disease. They received triptorelin depot or placebo every four weeks for six months.
Planned observation followed.
Pain and lesion measures improved more with the drug. Side effects affected 80% of actively treated people, mainly hot flashes. Symptoms recurred.
For that reason, only five people could be observed for 12 months after treatment. The abstract does not state the depot strength. It cannot be borrowed from Trelstar, Triptodur or another study.
Study of preserving ovarian function stopped because too few people joined
The NCT00090844 registry describes a randomized Phase 2 trial. It compared chemotherapy with or without Trelstar Depot 3.75 mg. The drug was given monthly into a muscle.
The women were premenopausal and had early-stage breast cancer. The main outcome was how long it took for periods to return.
The study enrolled 49 of the planned 138 people and stopped early because too few had joined. This does not show that the treatment failed to help. The cancer study does not establish routine use to preserve ovarian function or support fertility.
Other terminated prostate-cancer studies
The NCT00415246 registry describes a Phase 3 prostate-cancer study without a control group. It tested a new under-the-skin four-month sustained-release formulation. Early data did not support sustained blood levels for four months in everyone.
The study stopped for that reason. The record names Decapeptyl and estimates enrollment at 100. It posts no results or delivered amount.
This finding applies to one form of the drug and gives no basis for a dose. It does not change the approval of pamoate depots given into a muscle.
ANABRAQ, NCT01374087 randomized 32 men with recurrent prostate cancer after radiotherapy. It compared brachytherapy with or without one 22.5 mg triptorelin injection into a muscle. The preferred timing was two months before brachytherapy.
The trial stopped for slow enrollment; 31 men received treatment. The posted record says no analyses assessed biochemical failure-free survival or progression. Event counts alone do not show which treatment worked better.
Too few people or an early stop does not prove a drug had no effect. Among these studies, only the four-month study stopped because the new form did not work as planned.
Current US products and the animal drug OvuGel
FDA describes Drugs@FDA as its approved-product database. Its September 4, 2026 data page and 12-table archive list three prescription Trelstar products. They contain 3.75, 11.25 or 22.5 mg base equivalent per vial.
They also list one prescription Triptodur product at 22.5 mg base equivalent per vial. All four contain triptorelin pamoate. An exact openFDA ingredient query returns the same four human applications.
A current DailyMed search returns Trelstar, Triptodur and two OvuGel label records. The reviewed current OvuGel animal label lists an over-the-counter animal drug. It states “Not for Use in Humans” and identifies NADA 141-339.
OvuGel contains 100 micrograms of triptorelin base per mL. The drug is present as the acetate salt. The label gives a 2 mL amount placed in the vagina of weaned sows.
This is part of swine insemination. The 100 micrograms per mL refers to the base drug, not the acetate salt. These are different amounts.
The animal strength, volume, route and use do not apply to people.
The current Drugs@FDA archive showed no approved human triptorelin-acetate product. This finding does not affect the approved pamoate products or say whether acetate products are approved elsewhere.
Reader questions
What forms of triptorelin are approved for people in the United States?
The US products found for people are pamoate depots: Trelstar for advanced prostate cancer and Triptodur for central precocious puberty from age two years. Each has its own approved use, strength and time between doses.
Can Trelstar strengths be added or substituted?
No. The label says 3.75, 11.25 and 22.5 mg release the drug differently. They are not additive.
The corresponding depot strengths have four-, 12- and 24-week schedules.
Is Triptodur 22.5 mg plus 31 mg of pamoate?
No. The label gives 22.5 mg triptorelin base per vial, equal to 31 mg triptorelin pamoate. Both describe the same active material.
The 2 mL of sterile water is used to prepare that product, not as another dose.
Does the IVF trial establish an approved triptorelin-acetate dose?
No. It tested 15, 50 or 100 micrograms daily. That was part of a multi-drug IVF protocol.
The checked abstract does not state the route. Current US approval searches found human pamoate products. They found no approved human acetate product.
What strength was used in the endometriosis trial?
The checked abstract does not say. It reports a depot every four weeks for six months. The strength cannot be taken from a different product or study.
Is OvuGel a human triptorelin-acetate product?
No. OvuGel is an animal drug for weaned sows. Its label says it is not for use in humans.
The 100 micrograms/mL figure refers to triptorelin base. The drug is present as the acetate salt. This is not a human strength or schedule.
Can these labels and trials be combined into a hormone-optimization plan?
No. The labels cover advanced prostate cancer and central precocious puberty. Other studies concern IVF, endometriosis, cancer treatment or formulation testing.
They do not set a general wellness or fertility schedule. Nor do they set a schedule to optimize hormones.