Sermorelin Dosing Guide: Doses, Timing, and Nightly Protocol

Sermorelin is a 29-amino-acid analog of growth hormone releasing hormone (GHRH), the N-terminal fragment of the natural 44-amino-acid sequence that carries all of the receptor binding activity. It stimulates the anterior pituitary to release its own growth hormone in pulses rather than delivering GH directly, which is why dosing follows different logic than exogenous HGH. You are not replacing a hormone, you are timing a signal to land when the pituitary is already primed to fire.

Standard Sermorelin Dose Range

The dose range used in clinical and research settings is 200 to 500 mcg per injection, given once nightly. Most protocols start at 200 to 300 mcg and hold there for the first two to three months. The pituitary response saturates: past roughly 500 mcg, additional peptide produces very little additional GH release in most people, because the limiting factor is pituitary somatotroph capacity and somatostatin tone, not how much GHRH analog is present.

• Conservative start: 200 mcg nightly, useful if you are sensitive to flushing or head pressure
• Common starting dose: 300 mcg nightly for months 1 through 3
• Maintenance: 500 mcg nightly from month 4 onward if IGF-1 labs support it
• Upper end sometimes used clinically: 500 to 1,000 mcg, with diminishing returns above 500 mcg
• Cadence: once daily at night, 5 to 7 nights per week

Concentration Math: What to Draw on the Syringe

Compounding pharmacy sermorelin most often comes in 9 mg vials, though 5 mg and 15 mg vials also circulate. Reconstituting a 9 mg vial with 9 mL of bacteriostatic water gives 1 mg/mL, or 1,000 mcg per mL. On a U-100 insulin syringe where 100 units equals 1 mL, that means 10 units equals 100 mcg, which makes every dose in the working range a clean two-digit number.

• 9 mg vial + 9 mL BAC water = 1 mg/mL: 200 mcg = 20 units, 300 mcg = 30 units, 500 mcg = 50 units
• 9 mg vial + 4.5 mL BAC water = 2 mg/mL: 300 mcg = 15 units, 500 mcg = 25 units
• 5 mg vial + 5 mL BAC water = 1 mg/mL: 300 mcg = 30 units, 500 mcg = 50 units
• 5 mg vial + 2.5 mL BAC water = 2 mg/mL: 300 mcg = 15 units, 500 mcg = 25 units
• 15 mg vial + 7.5 mL BAC water = 2 mg/mL: 500 mcg = 25 units

The 1 mg/mL mix is the better default for most people. Draw volumes land between 20 and 50 units, far enough up the barrel that a one unit misread costs you 10 mcg instead of 20 mcg, and a 9 mL vial at 300 mcg nightly lasts 30 days, which is just past the 28-day preservative window. If you dose 500 mcg nightly, a 2 mg/mL mix on a 9 mg vial finishes in 18 days and wastes nothing.

Rather than working the ratios by hand, enter your vial size, water volume, and target dose into the sermorelin calculator, which is preloaded with the 9 mg and 9 mL defaults and renders the draw on a live syringe diagram. The general reconstitution calculator handles any other vial size.

When to Inject: The Sleep Window

The largest natural GH pulse of the day occurs during the first period of slow-wave sleep, typically 30 to 90 minutes after sleep onset. Sermorelin has a half-life of only 10 to 20 minutes, so the injection is timed to put peak plasma concentration into that window rather than to maintain any kind of steady level. Inject subcutaneously in the abdomen 30 to 60 minutes before you intend to be asleep.

1. Stop eating at least 2 hours before the injection, and 3 hours is better if the meal contained significant carbohydrate or fat.
2. Swab the vial stopper with 70 percent isopropyl alcohol and let it air dry for 10 seconds.
3. Draw your dose with a fresh 29-31 gauge U-100 insulin syringe, then tap out any air bubbles.
4. Pinch a fold of abdominal skin at least two inches from the navel and inject at 45 to 90 degrees.
5. Rotate the site each night across the abdomen, flank, and upper thigh to avoid local tissue changes.
6. Get into bed within 30 to 60 minutes. Do not eat after injecting.

A morning fasted dose is a secondary option for people who cannot dose at night, but it works against the circadian pattern and is generally considered less effective. Some physician protocols split the total into a nightly dose plus a post-workout dose, which exploits the exercise-induced GH pulse, though evidence for the split is thinner than for the single nightly injection.

Cycling and Duration

Sermorelin does not suppress endogenous GH production the way exogenous HGH does, because the hypothalamic-pituitary feedback loop stays intact and somatostatin still regulates the ceiling. That makes long continuous use plausible, and physician-supervised patients have run it for years. Even so, most practical protocols build in breaks, both to maintain pituitary receptor sensitivity and to control cost.

• 5 days on, 2 days off: the most common weekly pattern, usually taking weekends off
• 3 months on, 1 month off: a longer cycle used when tracking IGF-1 quarterly
• Continuous nightly: used in some supervised anti-aging protocols with periodic lab monitoring

Expect a slow curve. Sleep quality often improves in the first one to two weeks, which is the earliest reported effect. Recovery and body composition changes are gradual and typically become noticeable at 8 to 12 weeks. Skin and connective tissue changes take longer still. Anyone expecting HGH-like results in a month has the wrong mental model for what a secretagogue does.

Verifying It Works: IGF-1 Labs

Growth hormone itself is nearly useless to measure, because it is released in pulses and a single random draw can catch a trough. IGF-1 is produced in the liver in response to GH and has a half-life measured in hours, so it integrates GH exposure over roughly the previous day. That makes IGF-1 the standard marker for whether a GHRH protocol is doing anything.

1. Draw a baseline IGF-1 before starting, ideally in the morning.
2. Re-test after 8 to 12 weeks at a consistent dose and cadence.
3. Compare against the age-adjusted reference range, not a single universal number.
4. Adjust the dose upward only if IGF-1 sits in the lower half of the range and you tolerate the current dose well.

Sermorelin vs Other Growth Hormone Secretagogues

Sermorelin and CJC-1295 without DAC are both GHRH analogs and are used almost identically, nightly and fasted. CJC-1295 has a modestly longer half-life (around 30 minutes) and is generally considered more potent per microgram, while sermorelin carries the longer clinical record, including former FDA approval as Geref for pediatric growth hormone deficiency. Ipamorelin and hexarelin are a different class entirely: ghrelin receptor agonists that work through a separate pathway, which is why a GHRH analog plus a GHRP is the classic pairing. MK-677 is an orally active ghrelin mimetic with a 24-hour half-life, useful for convenience but blunt compared to a timed nightly pulse.

If you stack sermorelin with a GHRP, keep the injections in the same syringe or back to back, since the synergy comes from hitting both receptor pathways in the same window. Typical pairing is 300 mcg sermorelin with 200 to 300 mcg ipamorelin, nightly and fasted.

Side Effects and What to Watch For

Reported effects are usually mild and transient: injection site redness or itching, brief flushing, head pressure or mild headache in the first few nights, and occasional dizziness. Water retention and tingling in the hands appear mainly at the top of the dose range and usually resolve by lowering the dose. Because sermorelin produces physiological pulses rather than continuous supraphysiological GH levels, the joint pain, carpal tunnel, and acromegaly concerns associated with exogenous HGH are not typical at 200 to 500 mcg.

Sermorelin is not approved for anti-aging or performance use. It is prescribed off-label by physicians and otherwise sold as a research compound. Anyone with active malignancy, uncontrolled diabetes, or a known pituitary disorder should not be running GH secretagogue protocols outside medical supervision.