How a 5 kDa acylated peptide appears in electrospray and on a reversed-phase column, and what each confirms

Published 26 October 2026 · REVIVE LAB UAE Research Desk · 5 min read
With several arginines and lysines and a free carboxyl-terminal amide, tesamorelin carries four to seven protons in electrospray, appearing as a cluster of peaks between roughly 735 and 1,285 mass-to-charge units that deconvolute to a neutral mass near 5,136 daltons; the hexenoyl group is included in that mass and a value about 96 lower would indicate unmodified GHRH. On reversed-phase chromatography the acyl chain adds hydrophobicity, so tesamorelin elutes later than native hormone; the deamidated and oxidised forms elute earlier and are resolved. Purity is the main-peak area at 214 or 220 nanometres; the tyrosine at position 1 and the phenylalanine at 6 give some absorbance at 280 as well.

The spectrum

A peptide of this size sits between the few-charge spectra of short peptides and the broad envelopes of proteins. The 5+ and 6+ ions are usually the most intense. Isotope clusters are resolved on high-resolution instruments, so monoisotopic mass can be used, and the +16 oxidation satellite and the +1 deamidation shift are both detectable with care. Fragmentation of the amino-terminal fragment confirms the acyl group is on tyrosine 1.

The acetate counterion does not appear in the spectrum.

The chromatogram

A gradient of acetonitrile in water with trifluoroacetic acid separates tesamorelin from GHRH, from the deamidated and oxidised forms, and from synthesis-related impurities such as deletion sequences. The hexenoyl group shifts retention enough that unacylated peptide is easily distinguished. Detection at 214 or 220 nanometres captures the peptide bonds; 280 is weak because the sequence has only two aromatic residues.

The method and wavelength appear on the certificate with the purity figure.

On the certificate

Calculated mass, observed mass, difference; purity by area under the stated method; related substances including the two known degradants; counterion and water content; net peptide content. Identity for the batch is the mass comparison.

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 spectrum?

A peptide of this size sits between the few-charge spectra of short peptides and the broad envelopes of proteins. The 5+ and 6+ ions are usually the most intense. Isotope clusters are resolved on high-resolution instruments, so monoisotopic mass can be used, and the +16 oxidation satellite and the +1 deamidation shift are both detectable with care. Fragmentation of the amino-terminal fragment confirms the acyl group is on tyrosine 1.

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.