Peptides for Testosterone Production: Kisspeptin, HCG, and Clomiphene

Written by Adam Maggio | Medically reviewed by Dr. Mitchell Ross, MD, ABAARM

For men who want to increase testosterone naturally without exogenous testosterone, kisspeptin (a hypothalamic peptide), HCG (LH mimic), and clomiphene (SERM) can stimulate endogenous testosterone production. Kisspeptin is the most upstream intervention, working at the hypothalamic level to increase GnRH pulsatility.

The Case for Stimulating Natural Testosterone Production

Not every man with suboptimal testosterone wants to commit to lifelong exogenous testosterone replacement. For younger men, men who want to preserve fertility, or men with secondary hypogonadism (where the problem is in the hypothalamus or pituitary rather than the testes), stimulating endogenous testosterone production is a viable and often preferable alternative to TRT.

Kisspeptin: The Master Regulator

Kisspeptin is a neuropeptide produced in the hypothalamus that is the primary driver of GnRH (gonadotropin-releasing hormone) pulsatility. It is the most upstream regulator of the HPG axis. Kisspeptin deficiency or dysfunction is increasingly recognized as a cause of secondary hypogonadism. Research protocols using kisspeptin-54 (the most studied form) have demonstrated significant increases in LH, FSH, and testosterone in men with secondary hypogonadism. Kisspeptin is not yet widely available as a research peptide but represents an exciting frontier in testosterone optimization.

HCG: LH Mimicry

Human Chorionic Gonadotropin (HCG) mimics LH, directly stimulating Leydig cells in the testes to produce testosterone. HCG monotherapy can significantly increase testosterone in men with secondary hypogonadism and is often used as an alternative to TRT in men who want to preserve fertility. Typical dosing: 1,500–5,000 IU subcutaneously 2–3 times per week. HCG also increases intratesticular testosterone and maintains testicular size and function.

Clomiphene: SERM-Based Stimulation

Clomiphene citrate (Clomid) is a selective estrogen receptor modulator (SERM) that blocks estrogen feedback at the hypothalamus and pituitary, causing increased GnRH, LH, and FSH secretion. This stimulates the testes to produce both testosterone and sperm. Clomiphene is often used as a first-line treatment for secondary hypogonadism in men who want to preserve fertility. Typical dosing: 25–50 mg orally every other day or daily.

Choosing the Right Approach

The choice between kisspeptin, HCG, and clomiphene depends on the cause of low testosterone and the patient's goals. For secondary hypogonadism with a desire to preserve fertility: clomiphene or HCG. For maintaining testicular function during TRT: HCG or gonadorelin. For upstream hypothalamic dysfunction: kisspeptin (when available).