The best-proven peptides for fertility are already part of standard treatment: FSH and hMG (Menopur) to grow follicles, hCG to trigger egg maturation, and GnRH antagonists such as cetrorelix and ganirelix to stop early ovulation during IVF. All are FDA-approved and prescribed by fertility specialists.[2][4][5][8] Kisspeptin is a promising experimental IVF trigger, matching eggs in 95% of women in one small study, but it is not approved anywhere.[12]
For many women, the first step isn’t an injection at all. For ovulation problems from polycystic ovary syndrome (PCOS), the pill letrozole led to more live births than clomiphene in a large trial (27.5% vs 19.1%).[1] This guide covers female fertility and IVF. For sperm production, see our peptides for male fertility guide and the sexual health peptides hub.
Evidence-graded table
| Peptide or drug | Evidence level | What was shown | FDA status | Our profile |
|---|---|---|---|---|
| hCG (Novarel, Pregnyl, Ovidrel) | FDA-approved for this use | Triggers final egg maturation and ovulation[2][3] | Approved: ovulation induction, ART | hCG |
| hMG (Menopur) | FDA-approved for this use | Similar IVF outcomes to recombinant FSH[7] | Approved: ART[4] | hMG |
| FSH (Gonal-f, Follistim) | FDA-approved for this use | Grows multiple follicles; induces ovulation[5][6] | Approved: ovulation induction, ART | hMG |
| Cetrorelix, ganirelix | FDA-approved for this use | Prevent premature LH surge during stimulation[8][9] | Approved | Not available |
| Pulsatile gonadorelin (pump) | Small human studies | High ovulation rates in hypothalamic amenorrhea[14] | US product discontinued[15] | Gonadorelin |
| Kisspeptin-54 | Small human studies | Egg maturation in 95%; no moderate or severe OHSS in high-risk women[12] | Not approved | Kisspeptin-10 |
| Kisspeptin-10 | No fertility evidence | Not tested as an IVF trigger | Not approved; FDA safety-risk list[13] | Kisspeptin-10 |
| BPC-157 and other “wellness” peptides | No evidence, marketing only | No fertility studies | Not approved | BPC-157 |
How fertility hormones work
Ovulation runs on a relay of peptide and protein hormones. The brain releases kisspeptin, which triggers GnRH. GnRH tells the pituitary to release FSH, which grows follicles (the fluid sacs that hold eggs), and LH, which surges to release a mature egg. Fertility drugs copy or block each step:
- FSH and hMG supply follicle-growing hormone directly.
- hCG stands in for the LH surge.
- GnRH antagonists block the pituitary so an LH surge doesn’t release eggs before retrieval.
- Kisspeptin works at the top, prompting the body’s own LH surge.
Ovulation induction and IVF: the approved peptides
FSH and hMG. Recombinant FSH (follitropin alfa or beta) and hMG, which contains both FSH and LH activity, are approved to stimulate the ovaries for ovulation induction or IVF.[4][5][6] In a randomized IVF trial, recombinant FSH retrieved slightly more eggs (11.8 vs 10.0) while highly purified hMG produced a higher proportion of top-quality embryos.[7] Your specialist chooses based on your history and response.
hCG trigger. A single hCG injection, timed by your specialist, finishes egg maturation before egg retrieval or timed intercourse. Urinary hCG (Novarel, Pregnyl) and recombinant hCG (Ovidrel) are approved for this.[2][3]
GnRH antagonists. Cetrorelix (Cetrotide) and ganirelix are short peptides approved to prevent a premature LH surge in women undergoing ovarian stimulation.[8][9]
Risks. Gonadotropin labels warn about ovarian hyperstimulation syndrome (OHSS), where the ovaries swell and fluid shifts into the abdomen, and about multiple pregnancy.[4] ASRM’s 2024 guideline reviews who is at high risk and evidence-based ways to prevent it.[10] Call your clinic promptly if you develop marked abdominal bloating or pain, rapid weight gain, nausea and vomiting, reduced urination or shortness of breath during or after stimulation, since these can signal OHSS.[4]
Egg freezing and fertility preservation
Egg freezing uses the same peptide hormones as IVF. Follicle-stimulating injections such as FSH or hMG grow several follicles over a series of daily injections, a GnRH antagonist keeps the eggs from releasing early, and a trigger shot finishes maturation before retrieval.[4][5][8] The difference is that eggs are frozen instead of fertilized right away. The same OHSS and monitoring considerations apply.[10] If you are facing cancer treatment or another therapy that can harm fertility, ask your oncologist for an urgent referral to a fertility specialist, because timing matters.
Kisspeptin: an experimental trigger
Researchers in London have tested kisspeptin-54, a longer form of the hormone, as an alternative to hCG. In 53 women undergoing IVF, a single kisspeptin-54 injection matured eggs, and 23% had a clinical pregnancy.[11] In 60 women at high risk of OHSS, eggs matured in 95%, the live birth rate per embryo transfer was 45%, and no woman developed moderate, severe or critical OHSS.[12]
Those are encouraging but small studies without a large randomized comparison to standard triggers. Kisspeptin-10, the shorter version sold online, has not been tested as an IVF trigger, and FDA lists it among compounding substances that may present significant safety risks.[13]
Gonadorelin: effective by pump, unavailable in the US
Women with hypothalamic amenorrhea, where the brain stops sending GnRH signals (often from low body weight, intense exercise or stress), can ovulate again when GnRH is given in regular pulses by a small pump, mimicking the brain’s natural rhythm. A 2018 meta-analysis found high ovulation rates, mostly single pregnancies and a low risk of OHSS.[14] However, the US pump product, the Lutrepulse kit, is listed as discontinued.[15] Compounded gonadorelin given as daily injections does not reproduce those pulses.
Weight-loss drugs and conception
Some women with obesity use GLP-1 drugs before fertility treatment. Wegovy’s label says to stop it at least 2 months before a planned pregnancy because of semaglutide’s long half-life.[16] See our guide to semaglutide for PCOS for more.
Questions for your fertility specialist
- What is causing my infertility, and is an oral drug like letrozole a reasonable first step?
- Which stimulation protocol and trigger do you recommend, and what is my OHSS risk?
- How will we monitor my response to reduce the chance of multiples?
- Am I eligible for any clinical trials, such as kisspeptin trigger studies?
Partners’ fertility matters too; PT-141 vs Viagra covers sexual function treatments for men.
