# H-Frag Spray

> Research use only. Not for human or veterinary use. Supplied by Veracue Labs.

- Page: https://veracuelabs.com/product/h-frag-spray
- Category: Nasal Sprays
- Sizes and prices in USD: 5 mg at $71.49
- Certificate of analysis: none posted on the page. Request one for a specific lot at https://veracuelabs.com/contact-us.
- Prices are a snapshot from 2026-10-17. The product page shows the current price.

## Overview

H-Frag Spray is a spray-dispensed research material built on HGH Fragment 176-191, the sixteen amino acids FLRIVQCRSVEGSCGF taken from the tail end of human growth hormone and closed into a ring by a Cys7-Cys14 disulfide bond. The free peptide works out to C78H123N23O22S2 at an average mass near 1799.1 g/mol, filed under CAS 66004-57-7, and its first residue is phenylalanine, where AOD 9604 carries tyrosine. The 5 mg size comes with 45 sprays per bottle. Veracue offers H-Frag Spray for laboratory research use only.

## Product Details

### H-Frag Spray Specifications

Product name: H-Frag Spray
Peptide: HGH Fragment 176-191 (also Fragment 176-191, GH Fragment 176-191, H Frag)
Strength: 5 mg
Spray count: 45 sprays per bottle
Dispensing format: Spray-dispensed bottle
Sequence: FLRIVQCRSVEGSCGF (Phe-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe)
Length: 16 residues
Disulfide bond: Cys7 to Cys14, closing a ring inside the chain
Molecular formula (free peptide): C78H123N23O22S2
Average molecular weight: About 1799.10 g/mol
CAS Registry Number: 66004-57-7
Parent protein record: UniProt P01241, human somatotropin (mature-chain numbering used here)
Research designation: Research Use Only

Identity values describe the closed-ring free peptide and are reference data, not a lot result. Concentration and fill volume are lot details, recorded in the documentation for each lot and available through the contact page.

### The Peptide in Brief

The final sixteen residues of mature human growth hormone, positions 176 to 191, make up this peptide. Position 176 is phenylalanine, so the sequence opens with Phe. Neither end carries a cap or tag, leaving a free amine at the front and a free carboxylic acid at the back. Veracue supplies the sequence as one defined compound, never as a blend.

Catalogs and search results use several names for it: H Frag, HGH Frag, hGH Fragment 176-191, GH Fragment 176-191 and plain Fragment 176-191. Whatever the wording, the sequence, formula and CAS number above are the reliable way to confirm which material a listing describes.

### What H-Frag Spray Is Not

- Not a modified analogue. No tyrosine has been added and the native N-terminal phenylalanine is intact, which sets it apart from AOD 9604.
- Not intact growth hormone, which has 191 residues to this peptide’s sixteen.
- Not a retail wellness, nutrition or cosmetic item, and not meant for human or veterinary use.

## Research Focus & Mechanism Overview

### Naming and Numbering

### Is HGH Fragment 176-191 fifteen or sixteen residues long?

Sixteen. The two numbers are positions in the 191-residue mature hormone and both are counted, so 176 through 191 spans sixteen residues. The fifteen-residue stretch is 177-191, which starts at leucine and is the base sequence that AOD 9604 extends with a tyrosine.

### Why does the opening residue matter so much?

Because it is the only place the two look-alike peptides differ. The other fifteen residues are identical, so a document that prints FLRIVQCRSVEGSCGF describes H-Frag and one that prints YLRIVQCRSVEGSCGF describes AOD 9604, whatever the product name says.

### Residue-by-Residue Reading

The table lines up each position in the peptide with its position in the mature hormone. The two cysteines at peptide positions 7 and 14 are Cys182 and Cys189 in hormone numbering, and they are the pair joined by the disulfide bond.

Peptide position: Residue: Hormone position: Note

1: Phe (F): 176:
2: Leu (L): 177:
3: Arg (R): 178:
4: Ile (I): 179:
5: Val (V): 180:
6: Gln (Q): 181:
7: Cys (C): 182: Disulfide partner
8: Arg (R): 183:
9: Ser (S): 184:
10: Val (V): 185:
11: Glu (E): 186:
12: Gly (G): 187:
13: Ser (S): 188:
14: Cys (C): 189: Disulfide partner
15: Gly (G): 190:
16: Phe (F): 191:
The composition is plain. Aromatic side chains come only from the two phenylalanines at positions 1 and 16, and sulfur only from the two cysteines. The single acidic residue, Glu at position 11, is outweighed by the arginines at positions 3 and 8, so the charge at neutral pH sits near +1 once the two chain ends cancel. Closing the ring removes two hydrogen atoms, so the open-chain form would read about 2 Da heavier than the closed peptide.

### Document Lookup: What a Printed Value Means

Mislabeled paperwork is the usual source of confusion between these two peptides. The table translates the values most often seen on supplier documents.

If a document shows: It describes

Sequence beginning FLR: H-Frag, the unmodified fragment
Sequence beginning YLR: AOD 9604
Average mass near 1799.1: H-Frag with its disulfide closed
Average mass near 1801.1: H-Frag with the ring opened (reduced)
Average mass near 1815.1: AOD 9604 with its disulfide closed
CAS 66004-57-7: The H-Frag record
CAS 221231-10-3: The AOD 9604 record
YLR sequence with CAS 66004-57-7, or the reverse: A document that mixes two records; ask for a corrected one

AOD 9604, which is also written AOD-9604 or AOD9604, has the formula C78H123N23O23S2 and an average mass of about 1815.1 g/mol. The extra oxygen belongs to the tyrosine hydroxyl group.

### Compared With Full-Length Growth Hormone

Intact growth hormone folds a single 191-residue chain. H-Frag keeps only the closing sixteen, roughly one residue in twelve, together with the C-terminal disulfide bond between Cys182 and Cys189. Everything else in the parent chain is absent. Results gathered with the intact hormone describe a different molecule, and they should not be treated as data on this peptide unless the study names the 176-191 sequence itself.

Veracue provides molecular reference information here and gives no dosing, administration or usage guidance of any kind.

## Quality & Purity Standards

### What Lot Documentation Should Show

A certificate of analysis belongs to one lot. Match its lot number to your bottle before reading anything else, then work through the questions below.

Question: What a good answer looks like

Which molecule?: The FLRIVQCRSVEGSCGF sequence or CAS 66004-57-7, not the YLR sequence or CAS 221231-10-3
Does the mass agree?: A measured mass close to 1799.1 on an average basis, or 1797.9 monoisotopic, with the expected value printed beside it
Which chemical form?: Free peptide or a named salt, stated outright
How pure?: An HPLC result with its chromatogram and method
Who and when?: The testing laboratory and the test date
What about the liquid?: Concentration and fill volume for the bottle, stated on the lot record

Concentration and fill volume should come from the lot record, not be inferred from the 5 mg label or the 45-spray count. The certificate library explains how to request documentation for a lot.

### Mass Checks in Practice

Electrospray mass spectra normally show multiply charged ions, so an observed m/z has to be converted back to a neutral mass before it is compared with a reference value. For a peptide of this size the neutral mass is the number to match, and instruments that report monoisotopic values read about 1.2 Da below the average-mass figure.

Salt forms shift the expected number. A one-to-one acetate salt calculates to C80H127N23O24S2 at about 1859.1 g/mol, which is 60 g/mol above the free peptide. A lot that reports a salt should therefore be checked against the expected mass for that form and not against 1799.1. A 16 Da gap from the expected value is the signature of the tyrosine analogue, and a 2 Da gap suggests an opened ring.

### Questions About Verification

### What does an HPLC purity figure leave open?

It reports the share of detected material that elutes as the main peak under one set of conditions. It does not name that peak. A related peptide with similar retention could produce an equally clean trace, so identity needs a mass result from the same lot.

### Does an observed mass near 1799 settle everything?

It supports identity, but it says nothing about purity or quantity. Pair it with the HPLC result and the stated concentration and fill volume before treating a lot as fully characterized.

### What if the sequence and the CAS number on a document disagree?

Treat the document as unreliable until it is corrected. Some supplier sheets print one peptide’s sequence next to the other peptide’s CAS number, and the mass value shows which record the lot actually follows.

### Need lot documentation for H-Frag Spray?

Contact the Veracue team about records for a specific lot, or look through the certificate archive.

- Ask for lot records
- Open the certificate archive
- See the full catalog

## Compliance Notice

### Research Use Only Notice

H-Frag Spray is offered for laboratory research and analytical work only. Human and veterinary use fall outside its intended scope, and it is not a pharmaceutical, nutritional supplement, personal-care item or food. Veracue provides no dosing, administration or usage guidance of any kind. Researchers and institutions who buy it are responsible for lawful handling and for following their own institutional policies. See the Medical Disclaimer and the Terms and Conditions for sitewide policies.

### Scope of the Information Provided

The molecular data on this listing, meaning sequence, disulfide ring, formula, mass and CAS number, applies to the H-Frag peptide as a reference molecule. Identity, purity, concentration and fill volume for any particular bottle can be confirmed only from the documentation issued for its lot.

## Questions and answers

### What does H-Frag Spray contain?

It is built on HGH Fragment 176-191, a synthetic 16-residue peptide copied from the end of human growth hormone. The sequence is FLRIVQCRSVEGSCGF, and the product is for laboratory research only.

### How many sprays come in a bottle, and what strength is offered?

The listing is a 5 mg size with 45 sprays per bottle.

### What is the sequence of HGH Fragment 176-191?

Phe-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe. The cysteines at positions 7 and 14 form a disulfide bond, which makes Cys182 and Cys189 of the full hormone the matching pair.

### Is HGH Fragment 176-191 fifteen or sixteen residues?

Sixteen, because both position 176 and position 191 are counted. The fifteen-residue stretch is 177-191, which starts at leucine.

### Can H-Frag be mistaken for AOD 9604?

Yes, because suppliers often swap the names. They differ only at the first residue, phenylalanine in H-Frag and tyrosine in AOD 9604, so the sequence and mass on a document settle which one it is.

### How do the CAS numbers of H-Frag and AOD 9604 differ?

H-Frag is filed under 66004-57-7 and AOD 9604 under 221231-10-3. A document that pairs one peptide’s sequence with the other’s CAS number mixes two records.

### What mass should an H-Frag lot report?

About 1799.10 g/mol (average) for the closed free peptide, or about 1797.87 Da monoisotopic. A one-to-one acetate salt calculates to about 1859.1 g/mol, so the stated form matters.

### How does H-Frag relate to growth hormone?

It reproduces the last sixteen of the hormone’s 191 residues and keeps its Cys182 to Cys189 disulfide bond. It is a separate, much smaller molecule, not a different form of the hormone.

### What formula does the free peptide have?

C78H123N23O22S2 with the disulfide bond closed. The tyrosine analogue differs by one oxygen atom, C78H123N23O23S2.

### What should be checked on the certificate for this product?

The lot number against the bottle, the sequence or CAS number, an observed mass near 1799.1, the chemical form, an HPLC result, and the concentration and fill volume for the lot.

### Who is H-Frag Spray supplied to, and for what?

It is supplied to qualified researchers and institutions for laboratory research and analysis, with human and veterinary use excluded.

### Is there any usage guidance with H-Frag Spray?

No. H-Frag Spray is offered for laboratory research use only, and Veracue provides no dosing, administration or usage guidance of any kind.

More from Veracue Labs: https://veracuelabs.com/llms.txt