What makes ipamorelin different from other GH peptides?

Ipamorelin's defining feature is its selectivity — it stimulates GH release with minimal effects on cortisol, prolactin, and appetite. Older GHRPs like GHRP-6 and GHRP-2 raise GH effectively but also significantly elevate cortisol and (in GHRP-6's case) dramatically increase appetite. Ipamorelin achieves comparable GH release without these off-target effects, making it better tolerated for most patients.

How much GH does ipamorelin release?

At standard doses (1-3 mcg/kg or approximately 100-300 mcg), ipamorelin produces peak GH levels of approximately 10-30 ng/mL, occurring about 30-45 minutes after subcutaneous injection. The exact response varies by individual based on age, pituitary reserve, body composition, and fasting state. Combining with CJC-1295 can increase the GH response by 2-3x.

Does ipamorelin increase appetite?

Ipamorelin produces minimal appetite stimulation compared to other GHRPs. While it does activate the ghrelin receptor (which plays a role in hunger signaling), its appetite effects are generally mild or absent at standard doses. This is a major advantage over GHRP-6, which causes intense hunger in most users within 15-30 minutes of injection.

Why is ipamorelin combined with CJC-1295?

They work through different receptor pathways — ipamorelin through the ghrelin receptor (GHS-R1a) and CJC-1295 through the GHRH receptor. Stimulating both pathways simultaneously produces synergistic GH release approximately 2-3x greater than either peptide alone. The combination preserves pulsatile GH release patterns when using the no-DAC version of CJC-1295.

Is ipamorelin safe long-term?

Ipamorelin has not been studied in multi-year human trials, so long-term safety data is limited. Short-term human data shows a favorable side effect profile. Theoretical long-term concerns include IGF-1 elevation (cancer risk), glucose metabolism effects, and potential pituitary desensitization with continuous use. Regular monitoring of IGF-1, fasting glucose, and HbA1c is recommended during ongoing treatment.

When should I take ipamorelin?

Ipamorelin should be injected subcutaneously on an empty stomach — at least 90 minutes after your last meal. Most protocols recommend bedtime injection to augment the natural nocturnal GH surge during deep sleep. Some protocols include a second dose upon waking (still fasted) or 30 minutes before exercise. Avoid eating for at least 30 minutes after injection.

Why is ipamorelin vendor quality a concern?

Our testing of 261 samples from 41 vendors found that 69% of ipamorelin samples showed greater than 10% deviation between labeled and actual peptide quantity. This means most ipamorelin products deliver a meaningfully different dose than intended. Since ipamorelin's selectivity advantage is dose-dependent, receiving the wrong dose can either reduce effectiveness (underdosed) or eliminate the selectivity benefit (overdosed).

GHS-R1a Receptor Activation The ghrelin receptor (GHS-R1a) is expressed primarily in the anterior pituitary gland and the hypothalamus. When ipamorelin binds to GHS-R1a on pituitary somatotroph cells, it triggers intracellular calcium influx and GH release from secretory granules. This mechanism is complementary to — not competitive with — the GHRH receptor pathway used by sermorelin, tesamorelin, and CJC-1295. This complementary mechanism is why combining ipamorelin with a GHRH analog (most commonly CJC-1295 no-DAC) produces synergistic GH release — two different receptor pathways converging on the same somatotroph cells to maximize GH pulse amplitude. Why "Selective"?

The term "selective" specifically refers to ipamorelin's limited off-target effects compared to other GHS-R1a agonists. The selectivity appears to be a function of ipamorelin's specific binding characteristics: Cortisol: 1 at GH-releasing doses produces significant cortisol elevation (20-40% increase). 1 produces moderate cortisol elevation (10-20% increase). Ipamorelin produces negligible cortisol changes — typically fewer than 5% from baseline at standard doses. Prolactin: Similar pattern — older GHRPs cause meaningful prolactin elevation while ipamorelin does not. This is clinically relevant because chronic prolactin elevation can cause gynecomastia, sexual dysfunction, and menstrual irregularities. Appetite: While ipamorelin does activate the ghrelin receptor (which plays a role in app

Vendor Rankings

Independent rankings of peptide vendors based on aggregated lab data, COA transparency, community sentiment, and verified pricing. We publish everything — including the failures.

368+ samples tracked 192 vendors ranked 15 peptides tracked

All BPC-157 Tirzepatide Semaglutide CJC-1295 Ipamorelin GHK-Cu Retatrutide Tesamorelin

AGreat

B+Very Good

BGood

COkay

DPoor

EBad

FFraud

Ipamorelin Rankings

HUMAN TRIALS

368 samples across 192 vendors · Updated weekly from independent lab testing

#	Vendor	Avg score	Purity range	Tests	Verified $/mg	Grade	Profile
Grade B+ — Very Good
1	Reta-Peptide	8.5	—	16	—	B+	review →
2	Shenzhen Loga Tech LG LOGA	8.3	—	6	—	B+	review →
3	Zhejiang Yichenkang Biotechnology	8.2	—	7	—	B+	review →
4	Shanghai Sigma Audley SSA	8.1	—	8	—	B+	review →
5	Mai Peptide	8.0	—	7	—	B+	review →
6	SRY Labs	8.0	—	4	—	B+	review →
7	Xingruida XDR	7.9	—	3	—	B+	review →
8	Yiwu Aozuo Trading Co	7.9	—	10	—	B+	review →
9	SP Research	7.9	—	3	—	B+	review →
10	Zhengzhou Lan Yun Cosmetic Trading	7.7	—	2	—	B+	review →
11	TSC Top Supplements China	7.7	—	3	—	B+	review →
12	Shanghai ERP peptide Biotechnology	7.7	—	2	—	B+	review →
13	Shanghai OuDaXin New Material Technology Center	7.6	—	4	—	B+	review →
14	Qing Li Peptide	7.6	—	16	—	B+	review →
15	Shanghai Wibson Biotechnology WBS	7.6	—	4	—	B+	review →
Grade B — Good
16	Rethel Jinan New Energy Technology	7.5	—	3	—	B	review →
17	Shanghai Leader Peptide Biotechnology	7.4	—	3	—	B	review →
18	HkRoids	7.4	—	6	—	B	review →
19	Shandong Aishi Biotechnology	7.4	—	4	—	B	review →
20	ZLZ Peptide	7.3	—	6	—	B	review →
21	Shanghai Baoju	7.3	—	5	—	B	review →
22	ZePeptide	7.3	—	2	—	B	review →
23	Tianjin Ruiwang New Material Technology Co	7.2	—	5	—	B	review →
24	Haikou Mingheng Technology	7.2	—	5	—	B	review →
25	Wuhan Wansheng Biotechnology	7.2	—	15	—	B	review →
26	LN Peptides	7.2	—	2	—	B	review →
27	Uther	7.1	—	9	—	B	review →
28	LiliPeptide	7.0	—	9	—	B	review →
29	Zhengzhou Strong Peptide	7.0	—	3	—	B	review →
30	Peptide-S	7.0	—	4	—	B	review →
31	Oupeptide	7.0	—	7	—	B	review →
32	Xian Yihang Technology	6.9	—	3	—	B	review →
33	Bulk Peptide Wholesale	6.8	—	3	—	B	review →
34	WllyBIO	6.8	—	3	—	B	review →
35	Zen Peptides	6.8	—	3	—	B	review →
36	Shanxi Qianyecao Biotech QYC	6.8	—	5	—	B	review →
37	Nexaph	6.7	—	10	—	B	review →
38	HK Peptides	6.7	—	13	—	B	review →
39	Rhome Research	6.6	—	2	—	B	review →
Grade C — Okay
40	Planet Peptide	6.3	—	4	—	C	review →
41	Prime Peptides	6.0	—	5	—	C	review →
42	Suaway Lab Research	6.0	—	5	—	C	review →
43	Biolongevity Labs	5.9	—	4	—	C	review →
44	Paramount Peptides	5.9	—	7	—	C	review →
45	NextechLabs	5.9	—	4	—	C	review →
46	Precision Peptide Co	5.9	—	4	—	C	review →
47	Accelerate Labs	5.8	—	3	—	C	review →
48	PeptiLab Research	5.8	—	3	—	C	review →
49	Astro Peptides	5.5	—	7	—	C	review →
50	Injectify	5.5	—	4	—	C	review →

Verified $/mg = list price ÷ (avg tested qty / labeled qty). Vendors below the cutoff omitted from view.