Classic Growth Hormone Releasers Stack: Sermorelin with Ipamorelin, GHRP-2 or GHRP-6

What is the classic growth hormone releasers stack?

The classic growth hormone releasers stack pairs sermorelin, a copy of the brain's growth-hormone-releasing signal, with ipamorelin, GHRP-2 or GHRP-6. It is sold as sermorelin/ipamorelin and three-peptide sermorelin/GHRP-2/GHRP-6 blends, and you may also see the Hulk blend linked to it, though no Hulk vial we found contains its peptides. No trial has tested the stack as people use it; only short hospital tests gave sermorelin's molecule with GHRP-2 or GHRP-6. [7], [8], [1], [2]

The pituitary gland has two release switches for growth hormone: sermorelin presses the GHRH receptor, the other three press the ghrelin receptor. The "classic" trio comes from 1990s hormone research and US men's clinics; in community education groups the stack is now mostly sermorelin with ipamorelin at bedtime, and the older GHRPs are more often discussed than used, largely because of hunger. [13], [24]

What's in it, and what else is it called?

The core is sermorelin plus one ghrelin-type peptide: ipamorelin (the modern choice), GHRP-2 or GHRP-6 (the classic ones). Hexarelin and MK-677, a pill rather than a peptide, work on the same ghrelin switch and have their own guides.

A nickname does not fix what is in the vial. Only the label's amount of each peptide tells you what a dose contains; Hulk is the clearest example.

What is in each blend in this stack?

Two blends belong to this stack: sermorelin with ipamorelin, the most common, and the three-peptide sermorelin, GHRP-2 and GHRP-6 vial. Hulk is often linked to growth-hormone stacks, but its versions hold other peptides. No blend has been tested in people.

Amounts below are what labels and recall notices state, not doses, and labels are not proof: in a 2026 preprint of consumer-submitted tests, sermorelin was among the peptides most often failing both purity and amount, though its median measured amount was close to the label (97%). [25]

Sermorelin/ipamorelin

Sermorelin with ipamorelin, sold by research sellers and, in the US, compounded on prescription by telehealth clinics.

• Where sellers disagree: on the ratio, from 1:1 to 6:5. A 2021 FDA-noted recall of a compounded "Semorelin/Ipamorelin 3 mg" vial does not give the split. [26]
• What ipamorelin is claimed to add: a "selective" pulse without the cortisol and prolactin rise of the older GHRPs, shown in animals only; FDA found no human safety data for subcutaneous injections. [11]
• Stated amounts: the compounded vial's directions work out to 500 mcg of each on weeknights; see the combination schedules. [14]
• Regulators: FDA records name compounded sermorelin/ipamorelin vials recalled in 2019 and 2021 over sterility assurance. One lab report for a single lot of a telehealth vial with CJC-1295 added measured 99–104% of each labelled amount. [3], [26], [27]

Sermorelin/GHRP-2/GHRP-6

The classic three-peptide vial: sermorelin with both GHRP-2 and GHRP-6 at equal weights, so 300 mcg of powder holds 100 mcg of each. One protocol page calls it the "triple secretagogue" protocol. [28]

• Where sellers disagree: mainly on vial size. Do not confuse it with the healing "Tri-blend" (BPC-157, TB-500 and KPV).
• What the two GHRPs are claimed to add: GHRP-2 a strong growth-hormone pulse, GHRP-6 appetite. They press the same receptor: in rat pituitary cells each blunted the other, and together at full strength they released no more growth hormone than either alone. [22]
• Stated amounts: 100–200 mcg of each, one to three times a day, in the combination schedules. [28], [24]
• Regulators: a 2019 FDA-posted recall covered compounded 3 + 3 + 3 mg and 9 + 9 + 9 mg vials, and a 2021 review for FDA covered a nominated mix of the three. [3], [29]

Hulk

Hulk is often linked to growth-hormone stacks, but the name has no shared meaning. Every growth-hormone version we found pairs ipamorelin with CJC-1295 or tesamorelin; none contains sermorelin, GHRP-2 or GHRP-6.

• Where sellers disagree: on everything: CJC-1295 with or without DAC (long- and short-acting forms), and one maker sells tesamorelin with ipamorelin at 2:1 (Hulk) and about 4:1 (Hulk XL). [17], [5], [6] Community education groups also describe a compounded Hulk of tesamorelin, ipamorelin, AOD-9604 and MOTS-c.
• What the parts are claimed to add: CJC-1295 or tesamorelin replaces sermorelin as a stronger or longer-acting GHRH-type peptide; see their guides.
• Stated amounts and regulators: the Hulk pages give no dose, and no regulator notice names Hulk, though FDA warned a seller of tesamorelin and ipamorelin blends in August 2026. [30]
• Related stacks: the CJC-1295 and ipamorelin stack, the tesamorelin and ipamorelin stack and the healing and recovery stack.

Other blends you may see

Two-peptide and two-GHRP vials are listed in the names table. "Pulse", one seller's CJC-1295 with ipamorelin, is covered in that stack. [31]

Why do people combine sermorelin with a GHRP?

People combine them because the two kinds of peptide press different switches, and short hospital tests show a bigger growth-hormone pulse from both than from either. A bigger pulse is a rationale, not proof of better sleep, recovery or body composition. [7], [32]

• Two switches. Community education groups teach "one GHRH plus one GHRP" and quote large multiples for the combined pulse without a source. They disagree on two GHRPs together; the rat cell data favour picking one. [22]
• Milder than CJC-1295. Some who got flushing or a racing heart on CJC-1295 move to sermorelin; others find it too weak.
• Sleep or appetite. Bedtime serm/ipa is chosen mainly for sleep; GHRP-6 by people who want to eat more.
• Fewer injections. One blend or one syringe instead of two.

What does the evidence show?

The parts have been given together only as single injections into a vein or short drips in hospital, and one abstract reports repeated dosing without doses or numbers. Nothing shows that weeks of subcutaneous injections improve how people sleep, recover or look.

Sermorelin

Approved as Geref for a pituitary test and for children with growth-hormone deficiency, then discontinued in 2008; FDA later found this was not for safety or effectiveness reasons. Adult studies used about 1–2 mg a day, several times the 200–500 mcg website doses, and no study has tested those website doses. [10], [33], [34], [35] Full sermorelin evidence

Ipamorelin

Human studies gave it into a vein only: a dosing study in healthy volunteers and a trial after bowel surgery that found no benefit over placebo, with two deaths in the ipamorelin group (cause not established). FDA found no human safety data for subcutaneous injections. [36], [37], [11] Full ipamorelin evidence

GHRP-2

Approved in Japan only as a single 100 mcg IV test for growth-hormone deficiency. In healthy men, five days of 100 mcg subcutaneous injections shrank the growth-hormone response by about 40%, and IGF-1 did not rise. [12], [38] Full GHRP-2 evidence

GHRP-6

Small IV, oral and nasal hormone studies, mostly single doses. In an IV safety study of 18 volunteers, half had sweating and 44% a slow heart rate. [39] Full GHRP-6 evidence

The combination

• Sermorelin's molecule with GHRP-2: additive. In eight healthy men given each and both into a vein, both together beat GHRP-2 alone but not the two added up; the authors "were not able to demonstrate synergy". The same design was run in 15 children. [7], [40]
• GHRH with GHRP-6: more than the sum. The pair released far more growth hormone than the two added together and became a hospital test for growth-hormone deficiency, checked in 125 patients and 125 controls with no side effects and used up to age 96. [13], [8], [41] The extra effect needs a working hypothalamus: it was absent in people with pituitary-stalk disconnection and was no more than additive in acromegaly. [42], [32]
• Longer drips. In 26 critically ill adults, 21-hour drips of GHRH plus GHRP-2 raised growth hormone and IGF-1 more than GHRP-2 alone; in healthy men the extra effect was smaller in those with a higher body mass index. [43], [44]
• Repeated dosing. One abstract reports GHRP-2, GHRH or both given for 7–30 days, without doses or numbers; it says repeated dosing turned an additive response into a synergistic one. [45]
• The stack as people use it. The only record is a 2017 men's clinic review: 14 of 105 men on testosterone prescribed 100 mcg each of sermorelin, GHRP-2 and GHRP-6 three times a day met its criteria, and their IGF-1 rose from 159.5 to 239.0 ng/mL over about 134 days. There was no comparison group or systematic side-effect record. [24]
• Ipamorelin with sermorelin: never tested. We found no human study and no registered trial. [9]

How do the classic growth hormone releasers protocols line up?

These are each part's most common protocol from its own guide. They are not a stack protocol: no source tested them together, and people pick one ghrelin-type partner, not all three.

Schedules published for the combination

Each row is a complete schedule from one source.

How people line them up

Protocol pages and community education groups mostly give both peptides at the same time, at bedtime on an empty stomach (at least two hours after food), in one syringe or two. Morning fasted doses are the usual fix for poor sleep. GHRP-6 is sometimes timed before meals to use its hunger effect. Sources disagree on once versus two or three times a day, and none of these patterns has been compared. [50], [15], [28]

Plan it once. A nightly peptide and a twice-daily one, or a blend on weekdays only, are easy to mix up.

What are the overlapping risks and interactions?

Two growth-hormone releasers add up their growth-hormone side effects, the older GHRPs add cortisol, prolactin and hunger, and allergic reactions become harder to trace. None of these combinations has been safety-tested over weeks. [13], [53]

• Growth-hormone effects add up. Water retention, joint aches, numb or tingling hands and higher blood sugar are class effects, and the pair raises growth hormone more than one part. For GHRP-2, FDA lists reports of people needing more insulin. [53], [32]
• Cortisol and prolactin. GHRP-2 and GHRP-6 raise both; GHRP-6 about doubled them in healthy men. Ipamorelin's lack of this effect was shown in animals, not people. [13], [11]
• Hunger. Strongest with GHRP-6, moderate with GHRP-2; it works against weight-loss goals.
• Flushing and heart rate. Flushing followed most IV GHRH test doses and is often reported by adults, though under 1% of children had it in the Geref trials; after IV GHRP-6, 44% of volunteers had a slow heart rate. [13], [10], [39]
• Allergic reactions. Children on Geref often made antibodies to it and a few had hives, FDA raised immune reactions as a concern for injected ipamorelin, and FDA lists a report of elbow joint pain after a product containing both. In community education groups, delayed itchy welts are the most discussed harm. [10], [11], [54]
• Weaker response over time. GHRP-2's response fell about 40% within five days. [38]
• Multi-peptide vials. FDA records describe recalls of compounded sermorelin blends for sterility problems in 2016, 2019 and 2021. In community education groups the main harm is blend arithmetic, and one seller's own chart for a four-peptide vial works out to 500–2,000 mcg of GHRP-2 per injection. [19], [3], [26], [55]

Interactions. Glucocorticoid medicines such as prednisone blunt the response, according to the Geref label. No interaction with GLP-1 medicines, insulin, testosterone or other peptides has been studied; that is an absence of data, not evidence of safety. [10], [24]

Be especially cautious or avoid them in pregnancy (the Japanese GHRP-2 label says not to use it), under 18, with a current or past cancer or a pituitary tumour, with diabetes or prediabetes, with a history of allergic reactions to peptides, and in competitive sport. [12]

Legal and sport status (checked September 2026):

• United States: no approved product contains any part. Sermorelin can be compounded on prescription; FDA lists GHRP-2, GHRP-6 and ipamorelin among compounding substances that may present significant safety risks, and its advisers voted 0 to 12 against ipamorelin in 2024. [56], [53], [57]
• Canada: none is authorized. Health Canada named GHRP-2, GHRP-6 and sermorelin among seized unauthorized injectable peptides in 2025, and ipamorelin in 2026. [58], [59]
• Australia: all four are prescription-only medicines (Schedule 4), with no registered product. [60]
• Japan: GHRP-2 is approved only as a one-dose diagnostic test. [12]
• Sport: WADA prohibits all four at all times (section S2.2.4) on the 2026 and 2027 lists, and USADA calls an exemption for sermorelin "highly unlikely". [61], [62], [63]

What should be monitored?

No official guidance exists. What the label and studies of the parts measured:

• Growth-hormone axis: IGF-1; the clinic review also tracked testosterone, estradiol, LH and FSH. [24]
• Glucose metabolism: fasting glucose, insulin and HbA1c, because growth hormone raises blood sugar. [53]
• Thyroid function: the Geref label required thyroid tests before and during treatment. [10]
• Pituitary and adrenal hormones: prolactin and cortisol with GHRP-2 or GHRP-6. [13]
• Symptoms: swelling, blood pressure, joint aches, hunger, sleep and allergic reactions.

If a reaction appears, stop and talk to a clinician before restarting anything.

What happens when you stop?

Stopping has not been studied for any part or for the combination, and nobody has studied stopping one part while continuing another. [11]

• Short term: single test doses produced a growth-hormone peak 20–45 minutes later, a short-lived effect; there are no data on stopping after weeks of use. [7]
• Cold stop or taper: community educators disagree, and there is no evidence either way.
• Allergic reactions: can come back on restarting sermorelin. [10]

Premixed blend or separate vials?

A premixed blend saves an injection, but it fixes the ratio, hides which part caused a side effect, and has never been tested for stability with its parts mixed. Separate vials keep each dose adjustable and traceable.

• Mixing and stability. No study has measured sermorelin with ipamorelin or the GHRPs in one vial or syringe. The Geref label said to mix it just before use and discard the rest, and sellers give refrigeration instructions without stability data. [10], [16]
• The ratio is locked. In a 3 + 3 + 3 mg vial, every 100 mcg of sermorelin brings 100 mcg each of GHRP-2 and GHRP-6. If GHRP-6 makes you too hungry, halving the dose also halves sermorelin. [2]
• Tracking and troubleshooting. With separate vials a reaction can be traced to one part, and community educators advise starting each part alone first. With a blend it cannot.
• Units. Blend doses are weights of the whole powder. "300 mcg" of a 5 + 5 mg sermorelin/ipamorelin vial is 150 mcg of each; a "500 mcg" dose of a three-peptide blend held only about 200 mcg of sermorelin in one forum account. Work out syringe units for your own vial with the reconstitution calculator. [1], [64]

Common questions about the classic growth hormone releasers stack

Is the Hulk peptide blend sermorelin, GHRP-2 and GHRP-6?

No, not in any version we found. Hulk is sold as CJC-1295 with ipamorelin (with or without DAC), tesamorelin with ipamorelin, or even BPC-157 with TB-500. Check the label for each peptide's amount. [4], [17], [5], [6], [18]

Does sermorelin with ipamorelin work better than either alone?

Nobody has tested it. No study has given the two together. With GHRP-2, sermorelin's molecule added up rather than multiplied in one IV study of eight men, and a bigger growth-hormone pulse is not proof of better sleep or body composition. [7], [9]

Can you take GHRP-2 and GHRP-6 together?

They press the same receptor, so the second adds little in lab tests. In rat pituitary cells each blunted the other, and at full strength together they released no more growth hormone than either. No human study has compared them, and each adds cortisol, prolactin and hunger. [22], [13]

What is in a sermorelin/ipamorelin blend?

Most vials we found hold equal weights, such as 5 mg of each. Compounded vials have held 10 mg of each, or 18 mg of sermorelin with 15 mg of ipamorelin (recalled in 2019). [1], [14], [3]

Related guides

How this guide was researched

How this guide was made

This stack guide re-cites the original sources verified for the sermorelin, ipamorelin, GHRP-2 and GHRP-6 guides. New research covered studies of the parts together, blend names and contents (seller pages, recall notices, one lab report), the Hulk name, stability and regulator actions. Community education groups informed how use is described; no private post is quoted or linked.

The research file holds 94 records, 85 verified against the original page or abstract; this guide cites 64. Seller pages are cited only for listed contents and their own claims, never as evidence of purity or effect. Drafting used AI assistance under Doserly's editorial rules, followed by source checks and editorial review. It is general education, not medical advice.

Explore the sources