Kisspeptin and Testosterone: What the Research in Men Shows
Hormonal, Growth Hormone & Body Composition Research
Kisspeptin raises testosterone by working at the very top of the male hormone axis: it switches on the brain’s GnRH neurons, which prompt the pituitary to release LH, and LH tells the testes to make testosterone. In human studies from Imperial College London and Edinburgh, kisspeptin raised LH and testosterone in healthy men, sped up the natural rhythm of LH pulses, lifted testosterone in men with type 2 diabetes and low testosterone, and kept working in older men. Vistara Labs supplies it as a Kisspeptin 10 mg vial and a ready-mixed Kisspeptin Nasal Spray.
Findings
- A 90-minute kisspeptin-54 infusion in healthy men more than doubled mean LH against saline (10.8 vs 4.2 U/L) and raised testosterone (2005).
- A continuous kisspeptin-10 infusion raised testosterone from 16.6 to 24.0 nmol/L in healthy men, and a lower-rate infusion increased LH pulse frequency from 0.7 to 1.0 pulses per hour (2011).
- In men with type 2 diabetes and low testosterone, an 11-hour kisspeptin-10 infusion raised LH from about 3.9 to 20.7 IU/L and testosterone from about 8.5 to 11.4 nmol/L (2013).
- Healthy men in their late fifties had an LH response to kisspeptin at least as strong as men in their late twenties (2018).
- In men with low sexual desire, kisspeptin increased penile tumescence by up to 56% more than placebo (2023).
View product →How does kisspeptin raise testosterone?
Testosterone production runs down a chain of command. Kisspeptin neurons in the hypothalamus activate GnRH neurons; GnRH is released in pulses to the pituitary; the pituitary answers with luteinising hormone (LH) and follicle-stimulating hormone (FSH); and LH drives the Leydig cells of the testes to make testosterone. Kisspeptin sits at the top of that chain, which is why people born without working kisspeptin signalling never go through normal puberty (Seminara et al., N Engl J Med, 2003).
That position is what makes kisspeptin research distinctive. It does not supply testosterone, and it does not stand in for LH at the testes. It works through the body’s own GnRH, LH and testosterone response, so the whole axis stays in the loop. Our guide to what kisspeptin is covers its discovery and the KISS1 gene in more depth.
What the studies in men have shown
Healthy men: LH, FSH and testosterone
The first human data came from Imperial College London. In a double-blind, placebo-controlled crossover study, six healthy men received a 90-minute kisspeptin-54 infusion and a saline infusion in random order. Mean LH over the infusion reached 10.8 U/L against 4.2 U/L with saline, and FSH and testosterone rose significantly as well (Dhillo et al., J Clin Endocrinol Metab, 2005).
Kisspeptin-10 and the LH pulse
Kisspeptin-10, the shortest active form, was tested in men in Edinburgh. A single intravenous bolus produced a rapid, dose-dependent rise in LH, from 4.1 to 12.4 IU/L at 30 minutes at the most effective level. A continuous infusion over 22.5 hours raised serum testosterone from 16.6 to 24.0 nmol/L, and a lower-rate infusion increased LH pulse frequency from 0.7 to 1.0 pulses per hour, along with mean LH and the size of each pulse (George et al., J Clin Endocrinol Metab, 2011). Faster, larger LH pulses are direct evidence that kisspeptin speeds up the GnRH pulse generator that sets the pace of the whole axis.
Men with type 2 diabetes and low testosterone
Low testosterone is common in men with type 2 diabetes, and the same Edinburgh group asked whether kisspeptin could restore the signal. Five men with type 2 diabetes and low testosterone and seven healthy men received a kisspeptin-10 bolus, and the LH rise was comparable in both groups. Four of the men with diabetes then received an 11-hour infusion: LH rose from about 3.9 to 20.7 IU/L, testosterone from about 8.5 to 11.4 nmol/L, and LH pulse frequency increased. The authors described a potential therapeutic role for kisspeptin agonists in this group (George et al., Clin Endocrinol, 2013).
Older men
Testosterone tends to drift down with age, so Imperial compared five healthy men with a mean age of about 59 against five men with a mean age of about 29. The hypothalamic response to kisspeptin was fully preserved in the older men: their LH and FSH response was at least as strong as in the younger men, and at the highest level tested their LH response was larger. The difference sat further down the chain, in a smaller testosterone rise from the testes (Abbara et al., Neuroendocrinology, 2018).
Kisspeptin as a test of the hormone axis
Because kisspeptin acts on GnRH neurons, the size of the LH response shows whether those neurons are working. In 21 men with congenital hypogonadotropic hypogonadism and 21 healthy men, the peak LH rise after kisspeptin-54 averaged 12.5 IU/L in the healthy men against 0.4 IU/L in the men with the condition. Kisspeptin separated the two groups perfectly, an area under the curve of 1.0, against 0.88 for a standard GnRH test (Abbara et al., Neuroendocrinology, 2021).
| Study | Men | Result |
|---|---|---|
| Kisspeptin-54 infusion (2005) | 6 healthy | LH 10.8 vs 4.2 U/L; testosterone up |
| Kisspeptin-10 infusion (2011) | Healthy | Testosterone 16.6 to 24.0 nmol/L |
| Kisspeptin-10, type 2 diabetes (2013) | 5 with low testosterone | LH and testosterone up |
| Older vs younger (2018) | 10 healthy | LH response preserved with age |
| Hormone-axis test (2021) | 42 | Perfect separation of the groups |
Kisspeptin, testosterone and sexual function
The hormone work led Imperial into sexual function. In a randomised, placebo-controlled trial of 32 men with hypoactive sexual desire disorder, a 75-minute kisspeptin infusion modulated activity in the brain’s sexual-processing network while the men watched erotic videos, increased penile tumescence by up to 56% more than placebo, and increased happiness about sex. The authors described kisspeptin as having potential as the first pharmacological treatment for low sexual desire in men (Mills et al., JAMA Netw Open, 2023). The full set of desire and brain-imaging trials is in Kisspeptin for Libido: What the Sexual Desire Trials Found.
Kisspeptin compared with HCG and enclomiphene
All three are studied around the male hormone axis, at different points in it. Kisspeptin acts at the top, on GnRH neurons. Enclomiphene acts in the brain by blocking oestrogen’s brake on the axis, and HCG acts at the bottom, standing in for LH directly at the testes. Our comparisons of kisspeptin vs HCG and kisspeptin vs enclomiphene set them side by side, and HCG with TRT covers the testosterone-therapy side.
Kisspeptin-10 or kisspeptin-54?
Kisspeptin-54 is the full 54-amino-acid peptide and the major circulating form in humans, with a plasma half-life of 27.6 minutes in the 2005 study. Kisspeptin-10 is its last ten amino acids, the minimal sequence with full activity at the receptor, and acts more briefly. Both raised LH and testosterone in men, which is why both appear across this research.
Kisspeptin vial or nasal spray
- Vial: the Kisspeptin 10 mg lyophilised vial, reconstituted with bacteriostatic water; our kisspeptin reconstitution guide covers the arithmetic.
- Ready-mixed: the Kisspeptin Nasal Spray, 10 mg in 5 mL at about 350 mcg per spray; see buying kisspeptin nasal spray in Canada.
- In a stack: the Libido Trifecta Spray Stack pairs the kisspeptin spray with PT-141 (bremelanotide) and oxytocin sprays.
The human studies above gave kisspeptin by intravenous infusion or bolus, or by injection under the skin. Both formats are independently tested, with the certificate of analysis on our Lab Reports page, and ship from within Canada; ordering details are in buying kisspeptin in Canada.
Frequently asked questions
Does kisspeptin raise testosterone?
In human studies, yes. A kisspeptin-54 infusion raised LH and testosterone in healthy men (2005), a continuous kisspeptin-10 infusion raised testosterone from 16.6 to 24.0 nmol/L (2011), and an 11-hour infusion raised testosterone from about 8.5 to 11.4 nmol/L in men with type 2 diabetes and low testosterone (2013).
How does kisspeptin increase testosterone?
Kisspeptin activates the GnRH neurons in the hypothalamus. GnRH prompts the pituitary to release LH, and LH drives the testes to produce testosterone, so kisspeptin works through the body’s own hormone axis rather than supplying testosterone.
Does kisspeptin work in older men?
In a 2018 Imperial College London study, healthy men with a mean age of about 59 had an LH and FSH response to kisspeptin at least as strong as men with a mean age of about 29.
What is the difference between kisspeptin and HCG?
Kisspeptin acts at the top of the hormone axis, on the GnRH neurons in the brain. HCG acts at the bottom, standing in for LH directly at the testes.
Where can I buy kisspeptin in Canada?
Vistara Labs supplies kisspeptin as a 10 mg lyophilised vial and a ready-mixed 10 mg nasal spray for research use, shipped from within Canada by Canada Post Xpresspost.
Sources: Seminara SB et al. N Engl J Med. 2003. PMID 14573733. Dhillo WS et al. Kisspeptin-54 stimulates the hypothalamic-pituitary gonadal axis in human males. J Clin Endocrinol Metab. 2005. PMID 16174713. George JT et al. Kisspeptin-10 is a potent stimulator of LH and increases pulse frequency in men. J Clin Endocrinol Metab. 2011. PMID 21632807. George JT et al. Exploring the pathophysiology of hypogonadism in men with type 2 diabetes: kisspeptin-10 stimulates serum testosterone and LH secretion in men with type 2 diabetes and mild biochemical hypogonadism. Clin Endocrinol. 2013. doi:10.1111/cen.12103. Abbara A et al. Hypothalamic response to kisspeptin-54 and pituitary response to gonadotropin-releasing hormone are preserved in healthy older men. Neuroendocrinology. 2018. Abbara A et al. Kisspeptin-54 accurately identifies hypothalamic gonadotropin-releasing hormone neuronal dysfunction in men with congenital hypogonadotropic hypogonadism. Neuroendocrinology. 2021. Mills EG et al. Effects of kisspeptin on sexual brain processing and penile tumescence in men with hypoactive sexual desire disorder: a randomized clinical trial. JAMA Netw Open. 2023. PMID 36735255.
More on this: What Is Kisspeptin? The Reproductive Hormone Switch.
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