Dosing Protocols for Optimal Results

Introduction

Peptide protocols posted online look precise, but very little of that precision comes from dose-finding studies in people. For the growth hormone secretagogues, a few small human studies measured how much growth hormone (GH) a dose releases. For BPC-157, TB-500 and IGF-1 LR3, the numbers come from vendors, community guides and, indirectly, rodent work.

This page sets the doses users and vendors report beside what was actually tested; it isn't a recommendation. As of October 2026, none of these peptides is approved for muscle gain, fat loss or injury repair, and WADA's 2026 Prohibited List bans all of them for tested athletes (BPC-157 under S0, the others under S2). The rules for competitive sport have their own page.

Foundational Dosing Principles

Pulsatility and the "GH Bleed" Claim

The body releases GH in bursts, the largest usually during deep sleep. Short-acting compounds such as Mod GRF 1-29 and ipamorelin produce a brief spike, so users favor them for matching that pattern of pulsatile release.

Community guides often warn that CJC-1295 with DAC, which lasts about a week, causes "GH bleed": a flat, constant elevation that supposedly blunts the pituitary. The one study that measured this found otherwise. In 2006, Ionescu and Frohman sampled GH every 20 minutes overnight in healthy men aged 20-40, before and one week after a single 60 or 90 mcg/kg injection. GH pulses kept their frequency and size. What rose was the trough between pulses (about 7.5-fold), along with mean GH (46%) and IGF-1 (45%).

So the human data show pulses riding on a higher floor, not a loss of pulsatility. Whether that floor matters over months is unknown, because no study has followed long-term use. Our page on the long-term effects of peptide dosing covers what has been measured.

Receptor Saturation

Protocol guides often say GHRPs "saturate" at about 1 mcg/kg, so a 100 kg lifter supposedly gets no extra GH above 100 mcg per dose. The best-known human dose-response study doesn't show that plateau. In a 1990 trial in 18 healthy men, Bowers and colleagues gave IV GHRP-6 at 0.1, 0.3 and 1.0 mcg/kg. Mean peak GH rose from about 8 to 17 to 69 mcg/L, still climbing steeply at the highest dose tested.

What did appear at 1 mcg/kg was a roughly twofold rise in prolactin and cortisol, absent at the lower doses. So the figure marks where hormone side effects showed up in that IV study, not a ceiling on GH release.

Guides also warn that constant high doses make the growth hormone secretagogue receptor (GHSR) less responsive. Desensitization is plausible, but we found no human study testing it at user doses. The on/off cycling schedules users describe are built around this idea.

Synergy Between GHRH and GHRPs

Pairing a GHRH analog with a GHRP is the most common stack in user protocols, and here the idea has human support. The two act on different receptors on the pituitary's somatotroph cells: Mod GRF 1-29 on the GHRH receptor, and GHRPs such as ipamorelin on the GHSR, the receptor for ghrelin. In the same 1990 study, low GHRP-6 doses given with 1 mcg/kg of GHRH released more GH than the two would add up to separately. No trial has tested whether that extra GH changes muscle or fat.

Dosing Protocols: Growth Hormone Secretagogues

The doses below are what users and vendors report. Trial doses were weight-based and often given by IV, so the two aren't directly comparable.

GHRH Analogs

Mod GRF 1-29 (CJC-1295 without DAC). Its half-life is commonly quoted as about 30 minutes, though we couldn't find a human study behind that figure. Forum users most often describe 100 mcg per injection, some up to 300 mcg, taken with a GHRP one to three times a day. Most protocols keep a bedtime dose to add to the night's largest GH pulse, a timing nobody has tested for this peptide.

CJC-1295 with DAC. The drug affinity complex lets the peptide bind albumin in the blood, giving a half-life of 5.8-8.1 days in a 2006 trial in healthy adults. Community and vendor figures range from 500-1,000 mcg per week to 1-2 mg once or twice weekly. In the trials, single subcutaneous doses of 30-250 mcg/kg raised mean GH 2- to 10-fold for six days or more, and 30-60 mcg/kg was best tolerated. As of October 2026, FDA's list of risky bulk compounding substances says the agency "has identified serious adverse events associated with CJC-1295 including increased heart rate and systemic vasodilatory reaction."

GHRPs

Ipamorelin. Users favor it because it seems to raise GH without much effect on cortisol. That reputation rests mainly on a 1998 study in pigs, where ipamorelin didn't raise ACTH or cortisol even at doses more than 200 times those that released GH, while GHRP-2 and GHRP-6 did. Users commonly report 100-300 mcg per injection, one to three times a day, often with Mod GRF 1-29; vendor guidance lists 200-300 mcg two to three times daily. The only efficacy trial in people, using IV ipamorelin after bowel surgery, found no significant benefit over placebo.

GHRP-2 and GHRP-6. These older GHRPs raised cortisol in that pig study, and GHRP-6 raised cortisol and prolactin in the 1990 human trial. Users most associate GHRP-6 with intense hunger soon after injection, and some lifters pick it on purpose to eat more while bulking. Community guides commonly list 100 mcg per injection for either, with ranges up to 300 mcg. Our comparison of common bodybuilding peptides covers how these GHRPs differ.

Dosing Protocols: Healing and Growth Factors

As of October 2026, none of these has a published human dose-finding study, so every dose below comes from vendor guidance or user reports.

BPC-157

BPC-157 is a synthetic pentadecapeptide based on a sequence from a gastric juice protein. A 2025 systematic review in HSS Journal found 35 preclinical studies, one small retrospective human series, and "no clinical safety data." In rodents it consistently improved tendon, ligament, muscle and bone healing.

Users commonly report 250-500 mcg per day by subcutaneous injection, sometimes split into two doses, and some describe 1-2 mg a day for injuries. Many inject near the injury, hoping to raise the local concentration, but no human study has compared injection sites. In the 2003 rat Achilles tendon study often cited for tendon healing, the peptide was given by intraperitoneal injection, a systemic route, and still improved repair. As of October 2026, a placebo-controlled pilot of about 30 people in rotator cuff surgery (daily subcutaneous injections for 90 days) is registered at the University of Arkansas but not yet recruiting.

TB-500 (Thymosin Beta-4 Fragment)

TB-500 is often sold as thymosin beta-4, but the two aren't the same. Anti-doping chemists at Ghent University identified the peptide in TB-500 products as Ac-LKKTETQ, a 7-amino-acid fragment of the 43-amino-acid protein. Human trials have tested the full protein for skin wounds and eye injuries, not the fragment. As of October 2026, FDA says it "has not identified any human exposure data" for the fragment, and claims about angiogenesis come mostly from animal studies of the full protein.

Vendor guidance describes a loading phase of 2-2.5 mg twice a week for 4-6 weeks, then maintenance doses spaced from every one to two weeks to monthly, depending on the source. Forum users describe 2-5 mg twice weekly, or 0.5-2 mg daily or every other day, and many aren't sure whether their vials hold the fragment or the full protein.

IGF-1 Variants

IGF-1 LR3. This engineered analog binds poorly to the proteins that normally hold IGF-1 in check, which is why it's said to act longer. We found no measured source for the often-quoted 20-30 hour half-life and no published human study. Users take it hoping for muscle hyperplasia, but the growth that has been measured was in rats: three days of LR3 infusion enlarged the intestines by about 20%, which native IGF-1 didn't do at the same dose.

Forum users commonly describe 20-50 mcg a day, some up to 80-100 mcg, while vendor guides list 40-80 mcg. Many inject after training, sometimes into the trained muscle, and cycle 4-6 weeks on with an equal break; neither practice has been tested. Hypoglycemia is the risk users report most, and many eat carbohydrates soon after injecting.

IGF-1 DES. Vendors describe this truncated form as very short-acting, quoting a 20-30 minute half-life without a traceable source. Users describe 20-50 mcg injected into a target muscle 15-30 minutes before training. We found no human data on it.

Protocol Summary for Common Goals

Every row reflects community or vendor practice, not a tested protocol.

What We Still Don't Know

• Whether any GHRH plus GHRP stack changes muscle or fat in healthy adults.
• Whether the raised GH baseline from months of CJC-1295 with DAC carries risks that single-dose studies couldn't catch.
• What dose of BPC-157, TB-500 or IGF-1 LR3 does anything in people, and what dose is safe.
• How much of the gap between consistent rodent results and mixed user reports comes from gray-market product quality.