HGH Frag 5mg – Fragment 176-191 of growth hormone (C-terminal peptide)

What is HGH Frag 176-191 (5 mg)?

HGH Frag 176-191 is a short, C-terminal peptide fragment of human growth hormone (hGH), corresponding to amino acids 176–191. In the research literature it is described as a compound with a lipolytic and antilipogenic profile — designed to retain the "fat-burning" element of hGH, but without activation of the IGF-1 pathway and without the anabolic effect (muscle hypertrophy) characteristic of full growth hormone.

The same fragment appears in the literature also as AOD-9604 (a variant with an N-terminal modification). In the Peptology catalog, HGH Frag is assigned to the category peptides for skin, sleep and libido, though functionally it belongs to the group of metabolic / body composition control compounds.

It is a research compound — it is not a medicinal product and holds no authorization for clinical use. The clinical efficacy of the 176-191 fragment remains inconsistent across various reviews (some development programs were terminated due to inconclusive results). The product offered by Peptology is a research-grade reagent.

In the version offered by Peptology, HGH Frag is available in a 5 mg vial (nominal activity 5000 IU) as a lyophilized peptide with purity ≥ 99%, confirmed by independent laboratory analysis (CoA for every batch). The product is intended exclusively for scientific research and in vitro applications.

Variant: HGH Frag 5 mg

This page concerns one dosage variant — HGH Frag 5 mg (5000 IU). Each vial contains 5 mg of the lyophilized 176-191 fragment. A typical working reconstitution is 1 mL → 5 mg/mL, which makes it easier to measure small doses in a metabolic protocol.

HGH Frag is offered in the 5 mg variant. You will find the N-terminally modified variant of the same fragment as AOD-9604, and another metabolic compound — 5-Amino-1MQ.

How HGH Frag works — the lipolytic mechanism

In the research literature, HGH Frag 176-191 is described as a compound targeting fat metabolism. Below are the three most frequently studied elements.

Why the lack of IGF-1 activation matters

Full growth hormone acts both lipolytically and anabolically (through IGF-1), which is associated with effects such as tissue growth or an impact on carbohydrate metabolism. The 176-191 fragment was designed to separate the "fat-burning" effect from the rest — in published human studies, no increase in IGF-1 or worsening of the oral glucose tolerance test (OGTT) result was observed, with a good tolerability profile.

The same "clean lipolysis" mechanism is shared by AOD-9604 (a modified variant of this fragment). Compounds like 5-Amino-1MQ take a different metabolic route. This data comes from studies and does not constitute a claim about the effect of the research-grade product offered by Peptology.

Pharmacokinetics and pharmacodynamics (research framework)

HGH Frag is a short peptide fragment with a lipolytic profile. The most important research characteristics:

• Structure: C-terminal fragment of hGH (amino acids 176-191); the N-terminally modified variant = AOD-9604
• Targets: fat metabolism in adipocytes (↑ lipolysis, ↓ lipogenesis)
• IGF-1 profile: no increase in IGF-1 in published human series
• Glucose metabolism: no adverse effect on OGTT in studies
• Half-life: variable data; peptide fragments usually have a short t½
• Route of administration in protocols: most often subcutaneous, per the research protocol

Comparison: HGH Frag vs AOD-9604 vs 5-Amino-1MQ

Within the same category, it is worth comparing HGH Frag with two other metabolic compounds — the almost identical AOD-9604 and the NNMT inhibitor 5-Amino-1MQ. All concern fat metabolism, but via different routes.

HGH Frag and AOD-9604 are practically the same 176-191 fragment (AOD-9604 has a modified N-terminus), while 5-Amino-1MQ acts by a completely different route (NNMT). The comparison is indicative in nature and does not constitute a recommendation for use.

Research data on HGH Frag 176-191

The 176-191 fragment (as AOD-9604) was studied up to the clinical phase. Below are the most important observations — with the caveat that efficacy remains inconsistent.

Lipolysis and body composition

In preclinical models and ex vivo analyses of human adipose tissue, the 176-191 fragment was associated with stimulation of lipolysis and inhibition of lipogenesis. In animal models with chronic administration, a reduction in body weight and adipose tissue was reported.

Clinical studies (body weight control)

In a 12-week RCT, a moderate effect was reported (average loss of ~2.6 kg at 1 mg/day orally vs ~0.8 kg placebo), but the results of other series were variable. Some development programs were terminated due to inconclusive efficacy. This underscores that the clinical data are limited and mixed.

Safety profile

Published human studies describe good tolerability, no increase in IGF-1 and no adverse effect on glucose metabolism. These are research observations, not confirmation of the efficacy of the research-grade product.

Note: The information is presented for scientific and informational purposes and is based on the preclinical literature and studies on the 176-191 fragment / AOD-9604. It does not constitute medical advice, a recommendation for use or a claim about the effect of the research-grade product offered by Peptology.

HGH Frag profile at a glance

• C-terminal fragment of hGH (176-191) — the "fat-burning" element of growth hormone without the rest
• Lipolytic and antilipogenic profile — fat breakdown and limitation of its synthesis (models)
• Mechanism independent of IGF-1 — without an increase in IGF-1 and without worsening of OGTT in studies
• No anabolic effect — does not stimulate muscle hypertrophy
• Almost identical to AOD-9604; another metabolic compound: 5-Amino-1MQ
• Every batch with a CoA and purity ≥ 99%

All information provided refers to the research literature on the 176-191 fragment and should not be interpreted as a promise of effect, an instruction for use or a claim about the effect of the research-grade product offered by Peptology. Clinical efficacy remains inconsistent.

Research dosing protocols

In research protocols, HGH Frag is usually administered after reconstitution of the lyophilizate, most often subcutaneously:

• Typical working reconstitution: 1 mL → 5 mg/mL; calculate precise volumes in the peptide calculator
• Schedules are usually spread over time, in the context of metabolic / body composition protocols
• Often considered on an empty stomach (away from carbohydrate meals) in lipolysis research protocols
• Maximum 3 mL of solvent per vial

In combined protocols, HGH Frag is sometimes considered alongside other metabolic compounds, such as AOD-9604 or 5-Amino-1MQ. These schedules come from the research literature and do not constitute a recommendation for self-administration.

Side effects and safety

In published study series, the 176-191 fragment is described as well tolerated. Side effects are usually mild and transient. The data concern research on the molecule.

The safety profile in studies is described as favorable (no effect on IGF-1 or glucose), although clinical efficacy remains inconsistent. This information is scientific in nature and does not constitute an instruction for use.

Storage and reconstitution

HGH Frag is supplied as a lyophilized (freeze-dried) powder in a vial. In lyophilized form it is stable at room temperature, protected from light and moisture — refrigeration before reconstitution is not mandatory. After reconstitution, stability depends on the solvent used, with Peptide Matrix Water™ significantly extending the peptide's lifespan.

• Before reconstitution: room temperature, in the original packaging, protected from light and moisture. A refrigerator is not mandatory.
• After reconstitution with Peptide Matrix Water™: stability in the refrigerator +2 °C to +8 °C for up to 60 days under appropriate laboratory conditions — the stabilizing formula extends the peptide's lifespan relative to standard solvents.
• After reconstitution with bacteriostatic or sterile water: stability in the refrigerator +2 °C to +8 °C for up to 28 days under appropriate conditions. Do not refreeze the reconstituted solution.
• Reconstitution: in a laboratory setting, Peptide Matrix Water™, bacteriostatic water or sterile water for injection is usually used, depending on the protocol.
• Volume: maximum 3 mL of solvent (capacity of a standard vial). For a precise calculation of volume and units, use the peptide calculator.
• Homogenization: add the solvent slowly down the vial wall, without vigorous shaking, then wait 10–15 min. Swirl gently, do not shake.

Laboratory tip: With your order, you can add Peptide Matrix Water™ to the cart — a stabilizing solution designed for working with reconstituted research peptides. More in the article Bacteriostatic water vs acetic acid vs matrix water.

Frequently asked questions about HGH Frag 176-191

Is HGH Frag the same as AOD-9604?

Practically yes — AOD-9604 is the clinical name for the same C-terminal 176-191 fragment with an N-terminal modification, studied for lipolytic activity and safety without IGF-1 activation. Both concern fat metabolism.

Does HGH Frag affect IGF-1?

Published human study series show no increase in IGF-1 — this distinguishes the 176-191 fragment from full hGH. No adverse effect on glucose metabolism (OGTT) was observed either.

Are there RCTs on body weight?

Yes — there is a 12-week RCT with a moderate effect relative to placebo (~2.6 kg vs ~0.8 kg), but the results of other studies are mixed, and some development programs were terminated. Efficacy remains inconsistent.

Does HGH Frag build muscle?

No — the 176-191 fragment was designed for a purely lipolytic action, without an anabolic effect (hypertrophy) and without IGF-1 stimulation. This is the main difference from full growth hormone.

How is HGH Frag stored and reconstituted?

The lyophilized vial is stored at room temperature, protected from light and moisture. After reconstitution, stability depends on the solvent: with Peptide Matrix Water™ — up to 60 days in the refrigerator +2 °C to +8 °C; with bacteriostatic or sterile water — up to 28 days. Avoid refreezing.

Where to buy HGH Frag for research?

Peptology offers HGH Frag 176-191 (5 mg) as a research peptide with confirmed purity ≥ 99% and independent laboratory analysis for every batch. Fast shipping, discreet packaging and certificates of purity with the product. For scientific background, also see the article Peptides — what they are, how they work, main categories and safety profile.

Related products in the Peptology catalog

Researchers working with HGH Frag often also consider related metabolic and body composition control compounds. Each of the products below has a certificate of purity (CoA):

See the full catalog: Peptides for skin, sleep and libido · Peptides for weight loss · Peptides for energy and regeneration · All peptides · Blog on peptide research

Laboratory reconstitution

Laboratory protocol — reconstitution, research protocols, storage

Standardized protocol applicable to all research peptides in the Peptology catalogue. To calculate the solution concentration (mg/mL) for each vial, use the peptide reconstitution calculator.

60-second protocol

Quick reference

What you need

Five rules for reconstitution

Calculating concentration

Storage

Four mistakes to avoid

Shipping information

🚚 Shipping information

• Products in our warehouse – orders placed by 15:00 on working days are dispatched the same day, later orders on the next working day.

• Delivery with GLS to your address in 3–5 working days.

• Shipping costs €5 and is free from €50.

Frequently Asked Questions (FAQ)

Is this the same as AOD-9604?

Yes — AOD-9604 is the clinical name of the C-terminal fragment 176-191 (variant), investigated for lipolytic activity and safety without IGF-1 activation.

Does it affect IGF-1?

Published human series do not show an increase in IGF-1; the profile differs from full hGH.

What is the half-life?

Published data vary and are not standardized across all formulations; peptide fragments generally have a short t½ and various approaches to extend it are being developed.

Where can I buy HGH Frag in Europe and what does it cost?

You can buy HGH Frag in Europe online from Peptology, from 40,00 €. Delivery with GLS in 3–5 working days. Shipping is free from 50,00 €. Payment by card. Purity 99%+, with an HPLC report for every batch.

Laboratory Analysis

HGH Frag - 5 mg - Batch - 0226 - Purity