Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of Ipamorelin and TB-500 — mechanism, dosing, side effects, legal status, and pricing.
Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) originally developed by Novo Nordisk and later advanced by Helsinn/Nycomed. It is a selective ghrelin receptor agonist / growth hormone secretagogue (GHRP). Its defining feature versus older GHRPs (GHRP-2, GHRP-6, hexarelin) is that in preclinical and early clinical studies it raised GH without meaningfully increasing ACTH, cortisol, or prolactin. It is not FDA-approved for any indication; a Phase 2 trial for postoperative ileus failed to meet its primary endpoint and clinical development was discontinued. In the wellness/grey market it is sold as a research chemical and used off-label for anti-aging and body-composition goals despite no clinically validated human dose for those uses.
TB-500 is a synthetic N-acetylated heptapeptide (Ac-LKKTETQ) corresponding to amino acids 17–23 of thymosin β4, the actin-binding region of the native 43-residue protein. Despite widespread vendor labeling, TB-500 is NOT identical to full-length thymosin β4 (Tβ4); it is a short fragment containing the central actin-binding motif. It is sold as a research chemical and is not FDA-approved for any human indication.
Ipamorelin
TB-500
Category
Legal Status
Mechanism
Dose Range
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
Ipamorelin
TB-500
COA corpus from Disclosed Labs — independently tested batches only.
Ipamorelin
153
COAs
99.7%
Avg purity
17
Labs
TB-500
170
COAs
99.3%
Avg purity
16
Labs
Ipamorelin and TB-500 are both among peptides under FDA review for the Category 1 (503A) list; if added, they would require a prescription to be compounded by registered 503A/503B pharmacies — they are not yet authorized. In April 2026 the FDA removed 12 peptides from Category 2, which does not place them on the Category 1 list or authorize compounding. The FDA's Pharmacy Compounding Advisory Committee is advisory and meets July 23–24, 2026 to review nominations and make recommendations to the FDA.
The seminal preclinical characterization (Raun et al., 1998, PMID 9849822) established ipamorelin as the first GHRP-receptor agonist with GH-release selectivity comparable to GHRH, without raising ACTH or cortisol even at doses more than 200-fold above the ED50. Pharmacokinetic-pharmacodynamic modeling in healthy male volunteers (Gobburu et al., 1999, PMID 10496658) confirmed a roughly 2-hour half-life and dose-dependent GH response following IV infusion. The most advanced human study is Beck et al. (2014, PMID 25331030), a Phase 2, randomized, double-blind, placebo-controlled trial in 114 patients after bowel resection evaluating IV ipamorelin 0.03 mg/kg twice daily for postoperative ileus; the drug was well tolerated but did not separate from placebo on the primary endpoint (time to tolerance of solid food), and the sponsor (Helsinn/Nycomed) discontinued development. There are no completed registrational trials in adult GH deficiency, frailty, or body-composition indications. Ipamorelin is not FDA-approved for any indication. The 100–300 mcg dose range reflects community/compounding practice and is not clinically validated for anti-aging or body-composition use.
Key references
Animal studies of full-length Tβ4 show accelerated dermal wound reepithelialization (Malinda et al., 1999, PMID 10469335), increased angiogenesis, improved cardiac function after ischemic injury via an ILK/Akt pathway (Bock-Marquette et al., Nature 2004, PMID 15565145), and corneal healing (Sosne & Kleinman review, 2015, PMID 26241398). The short Ac-LKKTETQ peptide sold as TB-500 was characterized analytically in the anti-doping literature as a substance with suspected doping potential (Esposito et al., 2012, PMID 22962027); controlled human efficacy trials of injected TB-500 do not exist. Full-length synthetic Tβ4 (RGN-259) has been evaluated in Phase II/III ophthalmic trials for dry eye disease and neurotrophic keratopathy with mixed results — one Phase III NK trial met healing endpoints, while a later European Phase III missed its primary endpoint. No clinically validated human injection dose exists for the short TB-500 peptide; all circulating dosing figures derive from vendor and forum protocols, not controlled trials.
Ipamorelin (Performance) and TB-500 (Recovery) are in different categories and target different biological pathways. This is a common pattern in multi-compound research protocols. Researchers should monitor the biomarkers from both profiles and watch for interactions listed in each compound’s contraindications. Consult a licensed healthcare provider before combining any research compounds.
Cheapest verified Ipamorelin: live prices, vendors & COA data
The cheapest verified Ipamorelin by price-per-mg — a live board of in-stock vendors with COAs on file. Lab data from 17 labs across 163 COAs.
Cheapest verified TB-500: live prices, vendors & COA data
The cheapest verified TB-500 by price-per-mg — a live board of in-stock vendors with COAs on file. Lab data from 16 labs across 166 COAs.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Route
Frequency
Dosing Notes
Half-life
Side Effects
Contraindications
Lab Testing
Key references
Disclosed Labs