Deletion sequences, incomplete deprotection, oxidation, deamidation and the unacylated peptide — what a purity figure for tesamorelin excludes

Published 26 October 2026 · REVIVE LAB UAE Research Desk · 5 min read
Each of the forty-three couplings can leave a fraction of chains one residue short, so a 44-mer has forty-three possible single-deletion sequences, most eluting close to the parent. Protecting groups on arginine, asparagine, glutamine and the acidic residues may not all be removed, leaving heavier adducts. Methionine 27 oxidises and asparagine 8 deamidates during synthesis and storage. And a fraction of chains may escape the final acylation, giving unmodified GHRH 1-44 at a mass 96 daltons lower, which is active but unprotected. A purity figure by HPLC at one wavelength is the main-peak area against the sum of all these that the method resolves; counterion and water are accounted for separately as peptide content.

The classes

Deletions: lighter by one residue, assigned by mass. Incomplete deprotection: heavier by the group — 252 daltons for the arginine Pbf group, 56 for tert-butyl — and later eluting because the groups are hydrophobic. Oxidation: plus 16 at methionine 27, earlier eluting. Deamidation: plus 1 at asparagine 8, resolved by ion exchange better than reversed phase. Unacylated peptide: minus 96, earlier eluting, and notable because it is the native hormone.

Preparative purification removes most of these; what remains is reported.

What the figure covers

Area percentage under one method at one wavelength. Impurities that co-elute are counted as parent; those that do not absorb are not counted; peptide content is separate. Two 98 per cent figures from different methods are not the same statement. A certificate that states the method, the wavelength and the identified impurities has told you what its number means.

For this peptide the unacylated fraction and the two degradants are the lines to read.

Why it is here

Because a reader comparing certificates should know what a 44-mer can contain. It describes analytics and no use of the pack.

Tesamorelin is supplied by REVIVE LAB UAE for laboratory research use only, with identity by mass spectrometry and purity by HPLC for the batch. It is not for human or veterinary use, and no dosing, administration or protocol guidance is provided.

What it costs

FormatStrengthPriceAvailability
Tesamorelin Pack20 mgAED 1010In stock

Delivery is AED 40 flat and free on orders over AED 700. Payment is cash on delivery anywhere in the UAE, or USDT (TRC20) in advance, which takes 5% off the order total.

Frequently asked

The classes?

Deletions: lighter by one residue, assigned by mass. Incomplete deprotection: heavier by the group — 252 daltons for the arginine Pbf group, 56 for tert-butyl — and later eluting because the groups are hydrophobic. Oxidation: plus 16 at methionine 27, earlier eluting. Deamidation: plus 1 at asparagine 8, resolved by ion exchange better than reversed phase. Unacylated peptide: minus 96, earlier eluting, and notable because it is the native hormone.

Does REVIVE LAB UAE provide dosing guidance?

No. REVIVE LAB UAE supplies research materials and provides no dosing, administration or protocol guidance of any kind. Every product is sold for laboratory research use only and is not for human or veterinary consumption.

How fast is delivery in the UAE?

Stock is held in Dubai. An order confirmed before 4 PM Dubai time is dispatched the same working day, reaching Dubai and Abu Dhabi the same day and the remaining emirates within 24 hours. Delivery is AED 40 flat and free over AED 700.

Tesamorelin Pack — in stock, dispatched from Dubai
HPLC-verified, lot certificate on every carton, 24-hour delivery nationwide. Browse the catalogue → All peptides UAE

Related reading

Supplied for laboratory research use only. Not for human or veterinary consumption. REVIVE LAB UAE provides no dosing, administration or protocol guidance.