Best Peptide Stack for Muscle Growth in 2026

The best peptide stack for muscle growth, judged by how many research protocols use it and by the pharmacology behind it, is CJC-1295 without DAC paired with ipamorelin. The two compounds reach the pituitary through different receptors, a GHRH analogue and a ghrelin mimetic, and the growth hormone pulse from the pair is larger than from either alone. Protocols in circulation run 100 to 300 mcg of each per injection, once to three times a day, on 12-week cycles, at a list-price cost of roughly $50 to $220 a month at the Bureau's scored vendors. Everything on this page is research-use information about compounds sold as research chemicals, not a recommendation to anyone.

This guide sets the stack out in three tiers with a week-by-week table, covers the tesamorelin variant for visceral fat, explains why GHRP-6, hexarelin and MK-677 do not beat it, and costs each tier at vendor list prices checked in September 2026.

The stacks at a glance

Four combinations account for almost every "muscle stack" in circulation. Only the first answers the question in the title; the other three serve a second goal or a more advanced researcher.

Why CJC-1295 and Ipamorelin?

Growth hormone leaves the pituitary in pulses shaped by two hypothalamic signals: GHRH tells the somatotroph cells to load and release, somatostatin holds them back, and a third input, the ghrelin receptor, triggers release and dampens somatostatin. CJC-1295 is a synthetic GHRH analogue; ipamorelin is a synthetic pentapeptide acting on the ghrelin receptor. Because they push from two sides, the pulse after a combined dose is larger than the sum of two separate ones. The synergy was shown by Bowers and colleagues in 1990, who gave healthy men a GHRP with GHRH and measured a GH response beyond either agent alone. That study used GHRP-6 and native GHRH, intravenously, once; everything the community does with CJC-1295 and ipamorelin is an extrapolation from that class-level finding.

Ipamorelin earned its place for what it does not do. In the paper that introduced it, Raun and colleagues in 1998 reported GH-releasing potency comparable to GHRP-6 in animal models with no meaningful rise in ACTH or cortisol even at doses far above the GH-releasing dose; GHRP-6 and GHRP-2 raise both, and GHRP-6 drives hunger. That selectivity is the whole argument for ipamorelin over the older GHRPs, and the ipamorelin guide covers the receptor pharmacology.

CJC-1295 has one controlled human study worth knowing, and it is about the other version of the molecule. Teichman and colleagues in 2006 gave CJC-1295 with DAC to healthy adults and recorded a two- to ten-fold rise in plasma GH lasting six days or more, a 1.5- to three-fold rise in IGF-1 lasting nine to eleven days, and a half-life of 5.8 to 8.1 days. The stack on this page uses CJC-1295 without DAC, also sold as Mod GRF 1-29, which has a half-life of about 30 minutes and is dosed to ride the natural pulse rather than flatten it; there is no equivalent trial of the no-DAC form. The CJC-1295 dosage guide explains why the two versions are dosed on different schedules and why mixing them up is the most common error with this stack.

None of this gives a lean-mass number for the pair. The 2018 review by Sigalos and Pastuszak summarises the secretagogue literature the same way: the compounds reliably raise GH and IGF-1, and outcome data on body composition is thin. The nearest controlled reference points, trials of GH itself or of oral secretagogues, measure lean mass changes in the low single-digit kilograms over months.

The Stack Dosing Protocol: Beginner, Intermediate and Advanced

Three versions of the same stack circulate, differing in injection frequency rather than dose per injection. Ipamorelin has a saturating dose: past roughly 200 to 300 mcg the pulse does not grow, so more total GH exposure means another injection in another fasted window; the ipamorelin dosage page explains where that number comes from. Blend vials sold as "CJC-1295 / ipamorelin" are listed as a 1:1 mix (the Bureau has verified the split only for Apollo), which suits the 100/100 protocols; researchers who want more ipamorelin buy the two separately. None of the three protocols below is a clinical dosing schedule, because none exists for either compound in humans.

Tier 1: Beginner (one injection, before sleep)

100 mcg of CJC-1295 without DAC with 100 mcg of ipamorelin, once daily 30 minutes before sleep, fasted about two hours before and 20 to 30 minutes after. 8 to 12 weeks on, 4 off. About 6 mg of blend a month, one 10 mg vial. The first-cycle version, run to assess tolerance.

Tier 2: Intermediate (the most reported protocol)

100 mcg of CJC-1295 with 100 to 200 mcg of ipamorelin, twice daily, on waking fasted and 30 minutes before sleep. 12 weeks on, 4 off. About 12 mg a month at 100/100, two blend vials. The version most community reports describe, and the usual second cycle.

Tier 3: Advanced (three injections)

100 mcg of CJC-1295 with 200 to 300 mcg of ipamorelin from a separate vial, three times daily: waking, pre-training or mid-afternoon fasted, and before sleep, with the pre-training slot the one most often compromised. 12 to 16 weeks on, 4 to 6 off. About 9 mg of CJC-1295 and 18 to 27 mg of ipamorelin a month: three 10 mg vials at 200 mcg, four at 300 mcg. For researchers who have already completed Tier 2.

The CJC-1295 and ipamorelin stack page carries the full protocol tables for all three tiers, with timing and administration rows, the DAC question and whether the two can share a syringe.

The arithmetic that turns a vial into a syringe mark is where most mistakes happen: with 2 mL of bacteriostatic water in a 10 mg blend vial the concentration is 5 mg/mL, so a 200 mcg draw (100 mcg of each) is 0.04 mL, or 4 units on a U-100 insulin syringe. The blend calculator does this for any vial and water volume, the ipamorelin calculator and CJC-1295 calculator cover the two-vial version, and the reconstitution guide covers the mixing.

Week-by-Week Protocol Table

The 12-week shape most reports follow, assuming Tier 1 for the first fortnight and Tier 2 from week three, which is the usual progression.

Timing Considerations

Two pieces of GH physiology decide when the injections go in. The largest natural pulse of the day happens in the first phase of slow-wave sleep, so an injection 30 minutes before bed lands on top of it; and insulin is the main physiological brake on GH secretion, so an injection within two hours of a meal, especially a carbohydrate meal, is partly wasted. Hence the before-sleep and on-waking slots in every tier. Training adds a third window, 20 to 30 minutes before a session, so the pulse coincides with the exercise stimulus, which itself raises GH; the post-workout slot is poor if the session ends with a carbohydrate meal. No trial has compared one injection time against another for either compound.

Expected Results Timeline

Better sleep is the first and most consistent report, then faster recovery between sessions, then a slight increase in appetite, with the scale up a kilogram from water in the first fortnight and reference lifts moving from week three. Strength gains, visible changes in definition and less soreness follow through week eight, then a plateau, with sleep and recovery benefits persisting for as long as the stack runs. Community reports of 3 to 4 kg of scale weight at maintenance calories are easy to find, and that figure is water, glycogen and lean tissue together. Published GH-axis research in adults is far more modest: the 2009 trial by Sattler and colleagues of GH with testosterone in older men, and the one-year oral secretagogue trial discussed below, put lean mass changes in the low single-digit kilograms over months. That literature, not forum threads, is the benchmark.

Diet and Training Adjustments

A GH secretagogue stack does not add tissue on its own; it shifts the rate at which a calorie surplus and progressive overload are converted into muscle, and does nothing measurable without both. Most reports pair it with a surplus of 300 to 400 kcal a day, protein around 1.6 to 2.2 g per kilogram of body weight (the range the sports nutrition literature supports for resistance training regardless of any compound), and each muscle group trained twice a week with progression. The fasting rule around injections has to fit the meal schedule, the constraint most find hardest in Tier 3.

The Lean-Mass Alternative: Tesamorelin and Ipamorelin

Swap the GHRH half for tesamorelin and you get the one GH-axis peptide with phase 3 trials behind it. Tesamorelin is a stabilised 44-amino-acid GHRH analogue approved as Egrifta for excess abdominal fat in HIV-associated lipodystrophy. In the 2007 New England Journal of Medicine trial by Falutz and colleagues, 412 patients received 2 mg daily or placebo for 26 weeks, and visceral adipose tissue fell by about 15 percent on tesamorelin while rising slightly on placebo. A 2010 trial with a safety extension repeated the finding over 12 months and showed the fat returns when the compound stops. IGF-1 rose within weeks in both. That is a stronger evidence base than CJC-1295 without DAC will ever have, and it is why the tesamorelin and ipamorelin stack is the version clinics tend to prescribe.

It is not, however, a muscle trial. Lean mass changes in the tesamorelin studies were small, the population was not lifters, and the pair with ipamorelin has never been tested together. Tesamorelin plus ipamorelin is the right variant when visceral fat is the second goal, particularly for researchers over 40 whose waist is the measurement that matters, and it costs about three times as much per month: at Amino Club list prices checked 2026-09-08, a 10 mg tesamorelin vial is $69.99 and a 10 mg ipamorelin vial is $49.99, and the common pattern of 1 mg tesamorelin five days a week plus 250 mcg ipamorelin twice daily on those days uses about 22 mg and 11 mg a month, roughly $310. The tesamorelin before and after page builds the timeline from the phase 3 data, the ipamorelin versus tesamorelin comparison explains the tenfold difference in dose scale, and the tesamorelin dosage calculator handles the milligram-scale draws.

Comparing to Other Stacks: Why Not GHRP-6, Hexarelin or MK-677?

GHRP-6 with CJC-1295. The original pairing, and still cheaper per vial at some vendors. GHRP-6 produces a comparable or slightly larger GH pulse than ipamorelin, but it also raises ACTH and cortisol and drives hunger, which is exactly what Raun's 1998 data showed ipamorelin does not do. Reports on the GHRP-6 version describe more water and a harder time controlling intake; hard gainers sometimes want the appetite. The GHRP-6 guide sets out the trade.

Hexarelin with CJC-1295. The most potent GHRP per microgram and the fastest to stop working. Receptor desensitisation on hexarelin is documented within weeks, which forces short cycles, and it shares the cortisol and prolactin effect of GHRP-6. The hexarelin dosage guide covers the saturating dose and the cycle problem.

MK-677 (ibutamoren). The oral option, and the one with the best human trial. In the 2008 Annals of Internal Medicine trial by Nass and colleagues, healthy older adults on 25 mg daily for a year gained 1.1 kg of fat-free mass against a 0.5 kg loss on placebo, restored GH and IGF-1 to young-adult levels, and saw fasting glucose rise by about 5 mg/dL with reduced insulin sensitivity. MK-677 acts on the same receptor as ipamorelin, so it replaces the ipamorelin half rather than the whole stack, and its 24-hour action flattens the pulsatile pattern the injectable stack is built to preserve: a convenience trade with a glucose cost. The MK-677 guide and MK-677 before and after timeline cover it in full.

Sermorelin with ipamorelin. The same mechanism with a GHRH fragment that clears in minutes rather than half an hour, easier to obtain through clinics and weaker per injection. The sermorelin dosage guide shows how the protocols differ.

Adding IGF-1 LR3. The advanced layer: a long-acting IGF-1 analogue delivered directly, with reports of faster hypertrophy in 4 to 6 week blocks, hypoglycaemia as the documented hazard and no human trial data; the IGF-1 LR3 guide covers the glucose management that makes it a Tier 3 addition only. Recombinant GH and androgens sit outside this page; the peptides versus steroids comparison covers where they stand on effect size, side effects and legality.

What to Measure: Blood Work and Tracking

Every claim about this stack is a claim about the GH axis, and the GH axis has one readable marker. IGF-1, drawn in the morning before the injection, is the integrated signal of how much GH the pituitary has released over the preceding days; it is what Teichman measured, what Nass measured, and what tesamorelin's label reports. A research protocol takes it at baseline, week six and the end of the cycle. If it has not moved by week six, the product is underdosed, the fasting windows are not being held, or the timing is wrong; the peptide testing guide explains how to tell the first from the other two.

Fasting glucose and HbA1c belong on the same draws, because GH is counter-regulatory to insulin and the trials that measured it, the MK-677 trial and the tesamorelin programme among them, found a small rise in glucose or a fall in insulin sensitivity. Prolactin and cortisol only need checking if a non-selective GHRP such as GHRP-6 or hexarelin is in the stack. Outside the lab: morning weight, waist at the navel, three reference lifts logged every session, and sleep hours, with weight and waist repeated two weeks after the cycle ends, because what is still there after the water leaves is the number that counts.

Cost Breakdown

At research-vendor list prices the 10 mg blend vial is the unit that matters, and the monthly cost follows from the tier.

The vials-a-month column rounds up, because a part-vial is still a vial and a reconstituted vial is generally used within about four weeks. The advanced row uses two blend vials plus one 10 mg ipamorelin vial at 200 mcg, or two at 300 mcg; the ipamorelin vial is $49.99 at both Amino Club and PSPeptides, checked 2026-09-08. Bacteriostatic water and insulin syringes, listed in the reconstitution guide and injection guide, come on top, and a full 12-week Tier 2 cycle is four vials, about $240 at Amino Club list price before the first-order code. The older figure of $200 to $250 a month that still circulates for this stack, including in earlier versions of this page, predates 10 mg blend vials at these list prices; the cost per mg index tracks that shift across 18 compounds.

Side Effects Reported With This Stack

The side effects are GH effects rather than peptide-specific ones, and ipamorelin's selectivity keeps the list short. Reported most often: water retention of a kilogram or two in the first weeks, gone within days of stopping; tingling or numbness in the fingers, the carpal tunnel effect of fluid in the wrist and the reason a dose is stepped down rather than up when it appears; increased appetite; injection-site redness; flushing for a few minutes after an injection; and occasional headache. Fasting glucose can drift upward, as the MK-677 trial and the tesamorelin label both record, which is why it is on the blood work list. At Tier 1 and Tier 2 doses, serious adverse events are not commonly reported, and there is no long-term human safety data for the pair at all.

What Bureau readers report. The reports that reach the Bureau from readers who have run the pair, including the editor's own earlier cycles described in the first version of this page, match that list. Appetite is the effect most have to manage, usually through meal timing rather than by changing the dose; 1 to 2 kg of water that leaves within a week or two of stopping, and occasional finger tingling that resolves on its own, are the other two, and readers who tried the GHRP-6 version describe more of both. None of those reports describes a serious adverse event, and those who ran blood work before and after describe nothing out of range: a reassuring pattern, but a self-selected one and not a safety study.

Two groups have reasons to stay away: anyone with an active or recently treated cancer, because the GH and IGF-1 axis is mitogenic and every label in this class carries that warning, and anyone in tested sport, because GH secretagogues are on the WADA prohibited list. The peptide side effects guide compares the GH-axis effects with the other peptide classes.

Cycling and Duration

The standard shape is 8 to 12 weeks on and 4 weeks off, with 16 weeks the upper end for Tier 3. The reason to cycle is the feedback loop: sustained IGF-1 elevation raises somatostatin tone, and the ghrelin receptor becomes less responsive with continuous stimulation. Ipamorelin is reported to desensitise more slowly than hexarelin or GHRP-6, but no controlled study has tracked GH response to ipamorelin over months, so whether and when it fades is unknown. During the off weeks GH returns to baseline within days, and the off-cycle measurements are the ones that separate water from tissue.

Post-Stack: Keeping the Gains

Tissue gained on the stack does not disappear when it stops, provided training volume and protein intake hold. What goes is the water, in the first week, and some of the recovery advantage: reports consistently describe strength holding off the stack but moving more slowly than it did on it. A reference lift that holds through the off period was muscle, and one that falls back with the water was not. Some researchers run a lower "maintenance" dose year-round instead of cycling; the Bureau's peptide cycles guide sets out why the GH-axis compounds are the class where a full break has the clearest mechanistic argument.

Who Should and Shouldn't Use This Stack

The stack suits researchers with years of consistent training who can inject daily, hold a fasted window around each injection, and are measuring something specific over a 12-week block; it suits people over 35 better than people under 25, because natural GH output falls with age and the stack raises a pulse a younger pituitary already produces. It does not suit beginners, who will get more from a year of progressive training and a food scale; anyone who cannot tolerate an appetite increase; anyone with a cancer history; or anyone in tested sport. Nothing in the published data is sex-stratified, so nothing supports running the stack differently for women; the peptides for women guide covers where reported female protocols do diverge.

Related Stacks

The CJC-1295 and ipamorelin stack page is the deep dive on the pair, the tesamorelin and ipamorelin stack is costed vendor by vendor, the top 10 peptides for muscle growth ranks every GH-axis compound, and the Wolverine stack covers BPC-157 and TB-500 for training around an injury. KLOW and GLOW are GHK-Cu blends sometimes mistaken for muscle stacks; the Stack Builder returns whichever of these matches a goal, experience level and budget.

Key Takeaways

• CJC-1295 without DAC plus ipamorelin is the best peptide stack for muscle growth by usage and by mechanism: two receptors, one larger pulse, the cleanest GHRP side-effect profile.
• The three tiers differ by injection count, not dose; ipamorelin past its saturating dose adds cost, not effect.
• Published GH-secretagogue research puts lean-mass changes in the low single-digit kilograms over months; water arrives first and leaves first.
• Tesamorelin plus ipamorelin is the variant for visceral fat, backed by phase 3 data, at about three times the monthly cost.
• Monthly cost at list price is about $50 to $220 by tier, with a 10 mg blend vial at $50 to $66 across the scored vendors, checked September 2026.
• A research log records IGF-1, fasting glucose, HbA1c, weight, waist and three lifts at baseline, week six and the end. Cycles run 8 to 12 weeks with 4 off. Research use only; tested athletes should assume a positive test.

Frequently Asked Questions

What is the best peptide stack for muscle growth?

The most commonly run combination is CJC-1295 without DAC with ipamorelin. The pairing is popular because the two act through different receptors, a GHRH analogue and a ghrelin receptor agonist, so the growth hormone response to the pair is larger than to either alone. That mechanism is well described in the secretagogue literature, but it is not the same as trial evidence for lean mass in humans, and no controlled trial has measured lean mass on this pair.

How much CJC-1295 and ipamorelin are used together?

Protocols in circulation pair 100 mcg of CJC-1295 without DAC with 100 to 300 mcg of ipamorelin per injection, given once to three times daily. Beginner protocols run one injection before sleep, the most reported version runs two, and advanced protocols run three. These are community conventions rather than trial-derived doses, and raising the ipamorelin side past its saturating range mostly adds cost rather than effect.

When is a GH peptide stack injected?

Most protocols inject on an empty stomach, commonly 30 minutes before bed, because food and especially carbohydrate blunts the growth hormone response and the largest natural pulse occurs during early sleep. A second injection, where used, goes in the morning fasted or 20 to 30 minutes before training. The reasoning is physiological rather than the result of a timing trial.

How long before results show?

The changes people report on GH secretagogue stacks are gradual and modest. Sleep quality and recovery are reported in the first two to four weeks, body composition changes from week six onward, and a plateau after week eight. Water retention and appetite changes can appear early and are not the same as lean tissue. Published secretagogue trials in adults measure lean mass changes in the low single-digit kilograms over a year, not the figures gym forums quote.

Is tesamorelin with ipamorelin better than CJC-1295 with ipamorelin for muscle?

Not for muscle specifically. Tesamorelin is the only GHRH analogue with phase 3 trial data, and that data is on visceral fat in HIV-associated lipodystrophy, where it reduced visceral adipose tissue by about 15 percent over 26 weeks. It costs roughly three times as much per month as the CJC-1295 pairing at the Bureau's scored vendors. The tesamorelin version makes sense when visceral fat is the other target; the CJC-1295 version is the default for lean mass on a budget.

Is MK-677 a substitute for the injectable stack?

MK-677 is an oral ghrelin mimetic that acts on the same receptor as ipamorelin, so it replaces the ipamorelin half rather than the whole stack. In the one-year randomised trial in healthy older adults it added about 1.1 kg of fat-free mass against a 0.5 kg loss on placebo, with a small rise in fasting glucose and reduced insulin sensitivity. Its 24-hour action removes the pulsatile pattern that the injectable stack is built around. It is a convenience trade, not an upgrade.

How much does a CJC-1295 ipamorelin stack cost per month?

At list prices checked in September 2026, a 10 mg CJC-1295 / ipamorelin blend vial is $59.99 at Amino Club, $50.00 at Apollo Peptide Sciences and $65.99 at PSPeptides. A beginner protocol uses about 6 mg a month, one vial; the most reported protocol uses about 12 mg, two vials; an advanced protocol uses about 27 to 36 mg, three to four vials. That puts the monthly range at roughly $50 to $220 before bacteriostatic water and syringes.

Are peptide stacks for muscle growth legal?

These compounds are sold for research use only and are not approved for human performance use. Growth hormone secretagogues are also prohibited in tested sport. Anyone competing under an anti-doping code should assume these compounds will cause a positive test.

Sources cited on this page: Bowers CY et al, J Clin Endocrinol Metab 1990 (PMID 2108187); Raun K et al, Eur J Endocrinol 1998 (PMID 9849822); Teichman SL et al, J Clin Endocrinol Metab 2006 (PMID 16352683); Falutz J et al, N Engl J Med 2007 (PMID 18057338); Falutz J et al, J Acquir Immune Defic Syndr 2010 (PMID 20101189); Nass R et al, Ann Intern Med 2008 (PMID 18981485); Sattler FR et al, J Clin Endocrinol Metab 2009 (PMID 19293261); Sigalos JT and Pastuszak AW, Sex Med Rev 2018 (PMID 28400207). Research use only. Nothing on this page is medical advice.