Hormone peptides are peptides that act on the body’s hormone control systems, either by replacing a hormone, as prescription HGH does, or by signaling the brain and pituitary gland to release more of the body’s own hormones, as tesamorelin, sermorelin, CJC-1295 with DAC and kisspeptin-10 do.[1][8] Only HGH and tesamorelin are currently FDA-approved, each for specific conditions.[1][3]

This overview explains the two hormone axes these compounds target, what the evidence shows, how they differ from hormone replacement therapy, and the legal status of each.

What are hormone peptides?

Many of the body’s hormones are controlled by a chain of command. The hypothalamus in the brain releases a signal, the pituitary gland responds with its own hormone, and that hormone acts on a target gland or tissue. The compounds in this category plug into two of these chains:

  • The growth hormone axis. GHRH from the hypothalamus tells the pituitary to release growth hormone, which raises IGF-1. Tesamorelin, sermorelin and CJC-1295 copy GHRH; HGH is the growth hormone itself.[6][1]
  • The reproductive axis. Kisspeptin switches on the nerve cells that release GnRH, which tells the pituitary to release LH and FSH. In men, LH then signals the testes to make testosterone.[8][22]

Peptides that act on appetite and blood sugar, such as GLP-1 drugs, are also hormone-based, but we cover them under weight loss peptides and metabolic peptides.

Browse all hormonal peptides

See all 10 hormonal peptides ↓

How hormone peptides work

Growth hormone releasers. Sermorelin is the first 29 amino acids of natural GHRH, the part that carries its activity.[6] Tesamorelin is the full 44-amino-acid hormone with a fatty chain that slows breakdown.[3] In a phase 3 trial of 412 adults with HIV, daily tesamorelin raised IGF-1 by 81% and cut deep belly fat by 15.2% over 26 weeks, versus a 5% rise on placebo, without a significant change in blood sugar.[23] FDA approved it as Egrifta in 2010.[4] CJC-1295 with DAC binds to albumin in the blood, so one injection raised growth hormone for 6 days or more and IGF-1 for up to 11 days in healthy adults.[7] All three work only if the pituitary gland can respond, which is why sermorelin was also used as a diagnostic test of pituitary function.[5]

Kisspeptin-10. In healthy men, an IV dose of 1 microgram per kg raised LH about threefold within 30 minutes, and a 22.5-hour infusion raised testosterone from 16.6 to 24.0 nmol/L.[8] At matched doses, GnRH itself raised LH about three times more than kisspeptin-10.[9] Because kisspeptin acts upstream of GnRH, researchers are studying it as a test of whether the hypothalamus is working, for example in teenagers with delayed puberty.[22]

Kisspeptin-10 vs kisspeptin-54

Much of the attention around kisspeptin comes from a longer natural form, kisspeptin-54. Kisspeptin-10 is its last 10 amino acids, and both act on the same receptor. Kisspeptin-10 lasts about 4 minutes in blood, compared with about 28 minutes for kisspeptin-54.[9] The widely reported studies of egg maturation in IVF and of sexual desire in women used kisspeptin-54, not kisspeptin-10.[12][13] Those results should not be assumed to apply to the shorter form sold online. Our kisspeptin-10 profile separates the two in detail.

Peptides vs hormone replacement therapy

This section explains how the approaches differ. It is not advice on whether to use hormone therapy, which is a decision for you and a clinician.

Hormone replacementReleasing peptides
What is givenThe end hormone (for example testosterone, estrogen or growth hormone)A signal that asks the body to make more
Depends on working glandsNoYes
Approved examples hereHGH for growth hormone deficiencyTesamorelin, for HIV-related belly fat only

A few points follow from that difference:

  • Releasers need a gland that can answer. In a study of men of different ages, kisspeptin-10 raised LH at every age, but testosterone rose only in younger adults, suggesting the testes respond less with age.[11]
  • More exposure is not always more effect. In a 2026 Imperial College trial, daily 8-hour infusions of kisspeptin-10 kept LH and testosterone raised for 12 days, but a nonstop 5-day infusion lost its effect on LH.[10]
  • Feedback still applies. Compounds that make the pituitary release growth hormone stay under the body’s IGF-1 feedback; the Endocrine Society notes this makes oral growth hormone secretagogues hard to overdose.[14]
  • Approved replacement is condition-specific. HGH is approved for diagnosed growth hormone deficiency, and the Endocrine Society guideline says the diagnosis usually needs a stimulation test.[2] None of the peptides on this page is approved to treat low testosterone or menopause symptoms.

For aging specifically, the Endocrine Society’s 2023 statement says no therapy to raise growth hormone secretion or action is approved as an anti-aging treatment, and it describes evidence that harms of growth hormone and sex steroids outweigh benefits in unselected older people.[14] In a review of trials in healthy older adults, HGH added about 2 kg of lean mass but caused more swelling, joint pain and carpal tunnel syndrome.[15]

Safety, legality and sports rules

  • Prescription products: HGH and tesamorelin require a prescription, and tesamorelin’s label lists raised IGF-1, higher blood sugar and fluid retention among its warnings.[1][3][4]
  • Sermorelin: Geref was discontinued in 2008, and FDA determined in 2013 that this was not for safety or effectiveness reasons.[5]
  • Compounding: FDA lists kisspeptin-10 among bulk substances that may present significant safety risks (503A category 2), and it remained there on FDA’s May 2026 nominations list.[16][17] FDA’s advisers voted 0 to 13 against CJC-1295 with DAC for compounding in 2024,[18] and 0 to 11 against kisspeptin-10.[24]
  • HGH law: distributing HGH for anything other than an FDA-authorized treatment of a disease ordered by a doctor is a federal crime under 21 U.S.C. 333(e).[20]
  • Sport: WADA’s 2026 list bans growth hormone and GHRH analogs at all times, and bans kisspeptin and its agonists in male athletes.[19]

Related categories: growth hormone peptides and sexual health peptides, where kisspeptin’s libido research is covered.