Sermorelin Dosage Calculator

Sermorelin (also known as GRF 1-29 or GHRH 1-29) is a synthetic peptide corresponding to the first 29 amino acids of endogenous human growth hormone-releasing hormone (GHRH), which spans 44 amino acids. Developed in the 1970s and 1980s, sermorelin was the first GHRH analog approved by the FDA — under the brand name Geref — for the diagnosis and treatment of growth hormone deficiency in children. It was also approved for the diagnosis of pituitary GH reserve in adults.

Unlike recombinant human growth hormone (rhGH), which directly replaces endogenous GH, sermorelin acts upstream by stimulating the pituitary gland to produce and secrete its own growth hormone. This upstream mechanism is considered advantageous in some research contexts because it preserves the physiological negative feedback regulatory loop: if GH or IGF-1 levels rise too high, somatostatin from the hypothalamus suppresses further GH release, providing a built-in safety mechanism not present with exogenous GH administration. This regulatory preservation, combined with sermorelin's relatively short half-life (approximately 10–20 minutes in vivo), makes it a subject of ongoing research interest in anti-aging, body composition, and hormonal health domains.

Sermorelin binds to and activates the GHRH receptor (GHRH-R), a class B G-protein-coupled receptor expressed on somatotroph cells in the anterior pituitary. The receptor is coupled to adenylyl cyclase via G_s proteins, and its activation increases intracellular cyclic AMP (cAMP) and calcium concentrations, stimulating both GH synthesis (transcription of the GH gene) and the exocytosis of stored GH granules into the bloodstream.

The 29-amino acid N-terminal fragment of GHRH that constitutes sermorelin contains the full receptor-binding domain; the remaining 15 amino acids of endogenous GHRH contribute to stability rather than intrinsic activity. Sermorelin's short half-life in plasma results from rapid degradation by serum and pituitary peptidases, which is why CJC-1295 (a modified GHRH analog with added protease resistance and optional DAC albumin-binding) was developed as a longer-acting alternative. Nonetheless, sermorelin's short action produces natural GH pulses when administered at appropriate times, closely mimicking endogenous pulsatile GH secretion.

Sermorelin lyophilized powder (commonly available in 3 mg and 6 mg vials) is reconstituted with bacteriostatic water for injection. For a 6 mg vial, inject 3 mL of bacteriostatic water slowly against the glass wall of the vial. Allow to rest for 60 seconds, swirl gently until completely dissolved, and inspect for clarity — the solution should be clear and colorless. Do not shake.

A 6 mg vial reconstituted with 3 mL of bacteriostatic water yields 2,000 mcg/mL (2 mg/mL). A 200 mcg dose requires 0.10 mL (10 IU on a U100 insulin syringe). This is a very practical dosing volume. Use 27–31 gauge insulin syringes for subcutaneous injection into the abdomen, upper thigh, or upper arm. Because sermorelin is typically injected before sleep, the abdomen provides a convenient and consistent site.

Sermorelin research protocols for age-related GH decline and body composition studies most commonly employ daily subcutaneous injections, typically administered 30–60 minutes before sleep on an empty stomach. This timing capitalizes on the natural nocturnal GH secretory surge and ensures minimal interference from postprandial insulin elevation, which blunts GHRH-driven GH release.

Commonly referenced research doses range from 100–500 mcg per injection. The dose used in many anti-aging and body composition research protocols is 200–300 mcg per day. Some higher-dose protocols (up to 500 mcg) are used when more aggressive GH stimulation is desired, such as in muscle wasting or immune function research. In pediatric GH deficiency, Geref was typically dosed at 30 mcg/kg daily by subcutaneous injection.

A subset of research protocols combine sermorelin with a GHRP compound (most commonly ipamorelin or GHRP-2) at doses of 100–200 mcg sermorelin + 200–300 mcg GHRP, injected simultaneously before sleep, to exploit the synergistic GH-releasing effect of simultaneously activating the GHRH receptor and the ghrelin receptor on pituitary somatotroph cells.

Lyophilized sermorelin powder should be stored at 2–8°C and is stable for months when properly sealed and kept away from light. The reconstituted solution in bacteriostatic water should be stored at 2–8°C and used within 28 days. Sermorelin is a relatively labile peptide in solution compared to smaller, more structured peptides — it is more susceptible to temperature fluctuations and prolonged storage. Avoid leaving reconstituted sermorelin at room temperature for extended periods. Label vials with the reconstitution date. If the reconstituted solution appears cloudy or develops visible particles, discard and reconstitute a fresh vial.

Sermorelin has a well-established safety record from its years of pharmaceutical approval and use in pediatric growth hormone deficiency. The most common adverse effects are injection-site reactions (redness, swelling, tenderness), which are typically mild and transient. Headache and flushing occur in a subset of subjects. Sustained GH elevation — while considerably less dramatic than with exogenous rhGH due to the intact feedback loop — can theoretically contribute to edema, joint discomfort, and insulin resistance at high doses. Sermorelin is generally contraindicated in the presence of active malignancy (consistent with any GH-axis stimulating compound). It remains a research compound for laboratory investigation outside of its legacy pharmaceutical approval history.