Last Updated February 9, 2024

 February 9, 2024

Curious about Fragment 176-191 side effects?

HGH Fragment 176-191 is reported to offer the fat-reducing benefits of human growth hormone (hGH)—without the harms commonly experienced with long-term hGH treatment.

While HGH Fragment 176-191 has been “Generally Recognized As Safe” by a GRAS expert panel, it has not undergone full-scale review by the United States Food and Drug Administration, so questions about its safety remain.

In this article, we cover the potential benefits of HGH Fragment 176-191, before providing a detailed overview of its reported side effects.

Buy Fragment 176-191 from our top-rated vendor...

Disclaimer: contains information about products that are intended for laboratory and research use only, unless otherwise explicitly stated. This information, including any referenced scientific or clinical research, is made available for educational purposes only. Likewise, any published information relative to the dosing and administration of reference materials is made available strictly for reference and shall not be construed to encourage the self-administration or any human use of said reference materials. makes every effort to ensure that any information it shares complies with national and international standards for clinical trial information and is committed to the timely disclosure of the design and results of all interventional clinical studies for innovative treatments publicly available or that may be made available. However, research is not considered conclusive. makes no claims that any products referenced can cure, treat or prevent any conditions, including any conditions referenced on its website or in print materials.

What is Fragment 176-191?

HGH Fragment 176-191 is a peptide fragment of human growth hormone (hGH) that is increasingly studied for its fat loss and cartilage regeneration potential. While hGH is a 191-amino acid long, single-chain polypeptide, Fragment 176-191 contains just the C-terminus of hGH comprising amino acids 177 through 191 [1].

HGH has long been viewed as a candidate for treating obesity as it plays an important role in body composition [2] and has a strong effect on carbohydrate and lipid metabolism [3]. However, hGH treatment can produce a range of concerning side effects and has been deemed unsuitable for sustained long-term use in humans.

Research involving various hGH fragments has identified the carboxy terminus hGH 177-191 as the main lipid mobilizing domain of hGH—where its fat reducing benefits reside. Animal studies and clinical trials have shown that Fragment 176-191 helps reduce fat mass and body weight without causing hGH-associated side effects like glucose intolerance and hypertension.

fragment 176-191 side effects

HGH Fragment 176-191 Benefits

In this section, we cover three potential benefits of Fragment 176-191 administration.

Better Safety Profile Than Intact hGH

The primary benefit of using an HGH fragment like 176-191 is testing specific uses of hGH without exposing research subjects to the full range of side effects associated with intact hGH use.

To summarize the main effects of various HGH fragments [1]:

  • The amino-terminal region of hGH, specifically amino acids 1-15, 1-42, 6-13, and 32-46, exhibit strong insulin-potentiating action;
  • The central region of hGH, comprising amino acids 108-129, evokes high mitogenic responses;
  • The carboxy-terminus hGH 177-191 is the primary lipid mobilizing domain.

HGH Fragment 176-191 appears to offer all the lipid mobilizing benefits of hGH without causing known hGH-related side effects like hypertension, glucose intolerance, or insulin resistance.

In fact, clinical trials involving HGH Fragment 176-191 have shown that it produces adverse events at a rate indistinguishable from placebos [1]. This makes it an extremely interesting chemical for researchers wishing to safely investigate the potential fat loss benefits of hGH.

Fat Loss and Weight Loss Benefits

HGH Fragment 176-191 is exclusively composed of amino acids associated with lipid mobilization. The use of intact hGH to mobilize lipids has been extensively researched and there is ample evidence to show that hGH can:

  • Inhibit lipoprotein lipase activity (in adipose tissue) [4];
  • Reduce fat cell mass [5];
  • Stimulate lipolysis in adipocytes;
  • Reduce body fat mass [6]; and,
  • Influence fat distribution [7].

Research has shown that Fragment 176-191 appears to offer all of the above benefits. For instance, research involving mice and rats has shown that HGH Fragment 176-191 treatment results in:

  • Temporary reductions in blood glucose levels;
  • Sustained increases in plasma insulin levels [8];
  • Increased thermogenesis in skeletal muscle [9].

While these results have not yet been replicated in long-term clinical trials, they suggest that HGH Fragment 176-191 could potentially be used as a fat loss or anti-obesity treatment.

Cartilage Regeneration

HGH Fragment 176-191 appears to increase the effectiveness of hyaluronic acid (HA) injections when used to regenerate damaged cartilage. A 2013 study involving white rabbits found that test specimens injected with a combination of Fragment 176-191 and HA experienced faster and more significant cartilage growth compared with rabbits that received only HA injections [10].

Having reviewed the key potential benefits of HGH Fragment 176-191, it’s time to turn our attention to potential side effects.

Fragment 176-191 Side Effects | A Comprehensive Overview

Early animal studies involving Fragment 176-191 found that unlike intact hGH, it produced “no adverse effect on insulin sensitivity” when administered to Zucker rats [11] and “did not induce hyperglycemia or reduce insulin secretion…or cell proliferation” when administered to obese mice [12].

Subsequent human clinical trials conducted with HGH Fragment 176-191 found that it does not cause the harsh side effects associated with long-term hGH treatment [1]. A total of six trials involved doses ranging from 25 µg – 400 µg/kg bodyweight (via I.V. injection) and 9 mg – 54 mg (orally) have been conducted to date. Participants were given:

  • Physical examinations
  • Vital signs tests
  • Laboratory parameters
  • ECG tests
  • Blood glucose tests
  • IGF-1 level tests

Fragment 176-191 is typically sold in powder form and must be reconstituted with bacteriostatic water before being administered via subcutaneous injection. It is important to note that the Fragment 176-191 trials performed to date involved other routes of administration. That said, we can look to the findings of the two clinical trials where Fragment 176-191 was administered intravenously.

In the first dose-escalating study involving 15 healthy male subjects, each subject received three single dosages of either HGH Fragment 176-191 or a placebo as single dosages. During the course of the trial, a total of 29 adverse events were reported by 12 subjects. The most common adverse events (AEs) reported during the study were:

  • Headache (6 times)
  • Fatigue (4)
  • Hypoglycemia unspecified (3)
  • Dizziness (3)
  • Nasopharyngitis (2)
  • Cough (2)
  • Lethargy (1)
  • Tonsillitis (1)
  • Abdominal pain unspecified (1)
  • Application site reaction unspecified (1)
  • Injection site bruising (1)
  • Rhinitis seasonal (1)
  • Anorexia (1)
  • Injection site pain (1)

Researchers noted that there were no clinically significant changes in vital signs, physical examinations findings, clinical laboratory parameters, or ECG readings taken by test subjects who received Fragment 176-191 compared with those who received a placebo. No significant glycerol, glucose, or IGF-1 trends were observed.

In the second clinical study involving intravenously administered HGH Fragment 176-191, 23 obese subjects aged between 19 and 50 years old received four single doses of Fragment 176-191 at 25, 50, and 100 µg/kg, or a placebo. Each injection was given as a single I.V. infusion over a period of 20 minutes, separated by a 7-day washout period.

A total of 69.6% of the test subjects reported side effects and the total number of AEs was 118. The most common adverse events reported were:

  • Mild or moderate headaches
  • Feelings of chest tightness (possible related to Fragment 176-191 at 50 µg/kg)
  • Mild or moderate euphoria (reported by five subjects)

In total, there was no observable trend between the group that received HGH Fragment 176-191 and the placebo treatment group concerning the incidence of certain AEs. Compared with the group who received a placebo, there were no clinically relevant changes in:

  • Vital signs (blood pressure, radial pulse rate, and temperature)
  • ECGs recorded at any of the scheduled time points up to 24 hours post-dose
  • Glucose levels
  • IGF-1 levels

Together with the four other trials, HGH Fragment 176-191 treatment did not cause [1]:

  • Any increase in IGF-1 levels;
  • Any increase in insulin resistance;
  • Any impaired glucose tolerance; or,
  • Any negative effects on carbohydrate metabolism.

As noted earlier, a qualified GRAS expert panel has determined HGH Fragment 176-191 to be safe enough to be “Generally Recognized As Safe” (GRAS) under conditions of intended use in foods [1]. However, the short-term nature of the clinical trials outlined above indicates that further long-term study is required.

fragment 176-191 side effects

Where to Buy Fragment 176-191 Online? | 2024 Edition

While HGH fragment 176-191 is available for purchase online as a research chemical, its quality and purity can vary widely from one supplier to the next.

To help researchers along, our team has researched and tested a number of peptide companies to find the best source of fragment 176-191.

Based on our testing, we recommend the following stellar vendor for its commitments to product quality and customer satisfaction.


PureRawz is our preferred supplier of frag 176-191 and other research peptides.

Here’s why we rate so highly:

  • Proven Peptide Quality: At PureRawz, each batch of product is analyzed by a third-party lab and tested for 99% purity.
  • Reasonable Prices: At PureRawz, the cost of a single 10mg vial of fragment 176-191 is already fair at $71.48. The vendor also offers free shipping on domestic orders over $100.
  • Secure Payments: PureRawz' website is secured with the latest SSL technology so researchers can rest assured that their payment information and personal data will never be exposed. The vendor also facilitates a variety of payment methods, from credit cards to PayPal.
  • Responsive Service: PureRawz has a superb team of trained representatives on hand to answer any emails researchers may have. From shipping issues to pricing, researchers won’t have to wait long to receive a reply to their message.

Buy Fragment 176-191 from our top-rated vendor...

Bacteriostatic Water and Frag 176-191

Almost as important as a quality supply of Fragment 176-191 and other peptides are the complementary tools required for proper handling. A qualified researcher needs a formidable toolkit to correctly store, prepare, and administer peptides.

What is in this toolkit? Bacteriostatic water, alcohol wipes, and sterile syringes, to cite just a few items.

Stocking up on needed supplies can be a burden for researchers, as few trusted sources carry all the required products. However, it is a necessary evil in the journey to research.

Fragment 176-191 Side Effects | Verdict

For researchers curious about HGH Fragment 176-191 side effects and benefits, we hope that this guide has answered all the questions.

Interested in researching the fat-reducing benefits of hGH without exposing test subjects to the side effects associated with long-term hGH treatment? Fragment 176-191 might well be the peptide needed.

Order Frag 176-191 from our top-rated vendor here.


  1. Stier, Heike et al. “Safety And Tolerability Of The Hexadecapeptide AOD9604 In Humans”. Jofem.Org, 2021,
  2. Ho KK, O'Sullivan AJ, Hoffman DM. Metabolic actions of growth hormone in man. Endocr J. 1996 Oct;43 Suppl:S57-63. doi: 10.1507/endocrj.43.suppl_s57. PMID: 9076343.
  3. Vijayakumar A, Novosyadlyy R, Wu Y, Yakar S, LeRoith D. Biological effects of growth hormone on carbohydrate and lipid metabolism. Growth Horm IGF Res. 2010;20(1):1-7.
  4. Gravhølt CH, Schmitz O, Simonsen L, Bülow J, Christiansen JS, Møller N. Effects of a physiological GH pulse on interstitial glycerol in abdominal and femoral adipose tissue. Am J Physiol. 1999 Nov;277(5):E848-54. doi: 10.1152/ajpendo.1999.277.5.E848. PMID: 10567011.
  5. Rodríguez-Arnao J, Jabbar A, Fulcher K, Besser GM, Ross RJ. Effects of growth hormone replacement on physical performance and body composition in GH deficient adults. Clin Endocrinol (Oxf). 1999 Jul;51(1):53-60. doi: 10.1046/j.1365-2265.1999.00737.x. PMID: 10468965.
  6. Takahashi S, Satozawa N. The 20-kD human growth hormone reduces body fat by increasing lipolysis and decreasing lipoprotein lipase activity. Horm Res. 2002;58(4):157-64. doi: 10.1159/000065488. PMID: 12324712.
  7. Rosenbaum M, Gertner JM, Leibel RL. Effects of systemic growth hormone (GH) administration on regional adipose tissue distribution and metabolism in GH-deficient children. J Clin Endocrinol Metab. 1989 Dec;69(6):1274-81. doi: 10.1210/jcem-69-6-1274. PMID: 2685009.
  8. Ng FM, Bornstein J. Hyperglycemic action of synthetic C-terminal fragments of human growth hormone. Am J Physiol. 1978 May;234(5):E521-6. doi: 10.1152/ajpendo.1978.234.5.E521. PMID: 645904.
  9. Heffernan M, Summers RJ, Thorburn A, Ogru E, Gianello R, Jiang WJ, Ng FM. The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice. Endocrinology. 2001 Dec;142(12):5182-9. doi: 10.1210/endo.142.12.8522. PMID: 11713213.
  10. Kwon DR, Park GY. Effect of Intra-articular Injection of AOD9604 with or without Hyaluronic Acid in Rabbit Osteoarthritis Model. Ann Clin Lab Sci. 2015 Summer;45(4):426-32. PMID: 26275694.
  11. Cameron CM, Kostyo JL, Adamafio NA, Dunbar JC. Metabolic basis for the diabetogenic action of growth hormone in the obese (ob/ob) mouse. Endocrinology. 1987 Apr;120(4):1568-75. doi: 10.1210/endo-120-4-1568. PMID: 3549265.
  12. Ng FM, Sun J, Sharma L, Libinaka R, Jiang WJ, Gianello R. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone. Horm Res. 2000;53(6):274-8. doi: 10.1159/000053183. PMID: 11146367.
  13. Heffernan MA, Thorburn AW, Fam B, Summers R, Conway-Campbell B, Waters MJ, Ng FM. Increase of fat oxidation and weight loss in obese mice caused by chronic treatment with human growth hormone or a modified C-terminal fragment. Int J Obes Relat Metab Disord. 2001 Oct;25(10):1442-9. doi: 10.1038/sj.ijo.0801740. PMID: 11673763.

Scientifically Fact Checked by:

David Warmflash, M.D.

Table of Contents
    Add a header to begin generating the table of contents