Research Guide · 8 min read

Where to Buy Research Peptides in the UK: The Best Option for 2026

What makes Reta Research the UK's leading research peptide supplier

Over the last five years the UK research peptide market has grown a great deal, and that growth has brought a broad range in supplier quality. Plenty of storefronts draw from the same small pool of overseas synthesisers and resell the material with no independent checks. Reta Research was built on the opposite idea: HPLC testing on every batch, dispatch from a UK warehouse on every order, and a Certificate of Analysis available on request for each compound.

What makes Reta Research different

• Verified purity ≥99% — each batch is HPLC tested by independent laboratories, and the documentation is available to researchers on request.
• UK warehouse with same-day dispatch — place your order before midday and we post it the same day via Royal Mail 24, Saturdays included, with UK delivery inside 24 hours.
• Free UK delivery over £25 — no delivery charge on the standard service for orders above £25.
• Clear product specifications — each product page sets out the form, the purity, the storage requirements and the sizes on offer.
• Research-only positioning — products are sold purely for laboratory research use and are never marketed for human or veterinary purposes.

Agonists of the GLP-1, GIP and Glucagon Receptors

Incretin receptor agonists count among the most thoroughly investigated compounds in today's metabolic research. Reta Research carries the four most relevant members of this class:

Retatrutide

Retatrutide is a triple incretin receptor agonist that acts on the GLP-1R, GIPR and glucagon receptors all at once — which places it among the most mechanistically intricate compounds on offer for metabolic signalling research. Supplied in 10mg, 20mg, 30mg and 40mg vials.

Tirzepatide

Tirzepatide is a dual GIP/GLP-1 receptor agonist whose distinctive pharmacological profile makes it valuable to researchers looking at multi-pathway metabolic signalling, receptor pharmacology and gut–brain axis modulation. Supplied in 10mg, 20mg, 30mg and 40mg.

Semaglutide

Semaglutide is a GLP-1 receptor agonist and one of the most heavily studied metabolic peptides in the preclinical literature. Its strong receptor binding affinity and long half-life have made it a reference compound for GLP-1 signalling research. Supplied in 5mg, 10mg, 15mg and 20mg.

Cagrilintide

Cagrilintide is a long-acting amylin analogue used widely in research into the part amylin plays in appetite regulation, gastric emptying and energy homeostasis — including the ways it complements GLP-1 agonists. Supplied in 5mg, 10mg, 20mg and 30mg.

Secretagogues of Growth Hormone

Growth hormone secretagogues prompt the body's own GH release, either through GHRH receptor agonism (Tesamorelin) or through ghrelin receptor agonism (Ipamorelin). They sit at the centre of research into body composition, neuroendocrine regulation and metabolic homeostasis.

Tesamorelin

Tesamorelin is a synthetic GHRH analogue that attaches to GHRH receptors on the anterior pituitary and prompts endogenous growth hormone release. A hexenoyl group added at the N-terminus lengthens its half-life, and it serves as a reference compound for studying pulsatile GH secretion together with its downstream effects on body composition and metabolism. Supplied in 10mg.

Ipamorelin

Ipamorelin is a selective pentapeptide ghrelin receptor agonist. Its defining trait is its high selectivity — it drives pulsatile GH release without the rise in cortisol or prolactin seen with broader-acting GHRPs. That receptor specificity makes it a reference reagent for clean studies of GH-axis activation. Supplied in 10mg.

Peptides for Cognition

Nootropic peptides are among the busiest fields in modern neuropeptide research, especially those compounds that have come out of the Russian neuroscience literature.

Semax

Semax is a synthetic heptapeptide built from a fragment of adrenocorticotropic hormone (ACTH 4-7) and modified with a Pro-Gly-Pro extension that improves its stability. It is studied widely for its ability to upregulate brain-derived neurotrophic factor (BDNF) and to modulate central neurotransmitter systems, dopamine, serotonin and acetylcholine among them. Supplied in 10mg and 30mg.

Selank

Selank is a synthetic heptapeptide derived from tuftsin, an immunomodulatory tetrapeptide. Researchers turn to Selank for its anxiolytic and cognitive effects, achieved without the sedation that comes with conventional anxiolytics — which makes it an unusually clean tool for probing stress-response pathways. Supplied in 10mg.

Compounds for Mitochondria & Longevity

Mitochondrial dysfunction is now understood to be a core feature of both ageing and metabolic disease. The compounds gathered here hand researchers direct tools for examining mitochondrial function, energy metabolism and the pathways of cellular ageing.

NAD+

NAD+ (Nicotinamide Adenine Dinucleotide) is a foundational coenzyme at the heart of redox biology and cellular energy metabolism. Because it acts as a substrate for the sirtuins (SIRT1–SIRT7) and for PARP enzymes, it is indispensable when studying longevity pathways, DNA repair and age-related cellular decline. Supplied in 500mg.

MOTS-C

MOTS-C is a mitochondrial-derived peptide coded within the mitochondrial 12S rRNA gene rather than in nuclear DNA — a finding that recast mitochondria as active endocrine signalling organs. It serves as a reference compound in research on AMPK activation, insulin sensitivity and longevity. Supplied in 40mg.

SS-31

SS-31 (Elamipretide) is a mitochondria-targeted tetrapeptide that homes in selectively on the inner mitochondrial membrane, where it stabilises cardiolipin and curbs the production of reactive oxygen species. It ranks among the most thoroughly investigated peptides in oxidative stress and cardioprotection research. Supplied in 50mg.

Peptides for Tissue Repair & Regeneration

Tissue repair is one of the most actively researched areas in the peptide field, with applications that run from musculoskeletal regeneration through to the study of dermatological pathways.

BPC-157 / TB-500 Mix

The BPC-157 / TB-500 Mix brings two heavily studied tissue repair compounds together in one vial — 10mg of Body Protection Compound-157 alongside 10mg of Thymosin Beta-4 Fragment 17-23 — letting researchers explore complementary repair pathways within a single reagent. Supplied at 20mg combined.

TB-500

TB-500 is the active 17-23 fragment of full-length Thymosin Beta-4, keeping the LKKTETQ sequence that governs actin sequestration and the modulation of polymerisation. It offers a focused reagent for looking into actin dynamics, cellular migration and tissue repair pathways. Supplied in 10mg.

GHK-Cu — Tripeptide Copper Complex

GHK-Cu is a synthetic copper peptide complex, glycine, histidine and lysine bound to a copper(II) ion. The distinctive copper-binding behaviour it shows makes it a reference compound for studying redox-mediated cellular signalling, collagen synthesis and matrix remodelling. Supplied in 50mg.

KLOW

KLOW is a combination peptide formulation that draws four heavily studied compounds — BPC-157, TB-500, KPV and GHK-Cu — into one 80mg vial. Since each component works on complementary biological pathways, the result is a single reagent suited to multi-pathway tissue protection research.

Specialist Research Peptides

IGF-LR3

IGF-LR3 is a synthetic IGF-1 analogue carrying a 13-amino-acid N-terminal extension and an arginine substitution at position 3 — modifications that sharply lower its affinity for IGF-binding proteins and lengthen its functional half-life. It stands as one of the most thoroughly studied IGF-1 analogues in research on cellular proliferation and anabolic signalling. Supplied in 1mg.

PT-141 (Bremelanotide)

PT-141, also called Bremelanotide, is a cyclic heptapeptide derived from Melanotan II that acts as a non-selective melanocortin receptor agonist. Where vasoactive compounds work peripherally, PT-141 works centrally through the nervous system — which makes it a distinctive reference compound for research into neuroendocrine and central arousal pathways. Supplied in 10mg.

Accessories for the Laboratory

Reconstitution calls for the right diluent, and Reta Research keeps pharmaceutical-grade Bacteriostatic Water in stock for laboratory use.

Bacteriostatic Water 10ml

Bacteriostatic Water 10ml is a sterile, multi-use diluent solution for laboratory and reconstitution work, made to strict pharmaceutical-grade standards. A must-have to pair with any lyophilised peptide order.

Placing an order with Reta Research

Ordering from retaresearch.co could not be simpler:

1. Look through the full catalogue at retaresearch.co/collections/all.
2. Choose your compound and the dosage size you need.
3. Work through checkout — Reta Research takes all the major UK cards.
4. Get same-day dispatch confirmation on orders placed before midday, Monday to Saturday.
5. UK delivery arrives inside 24 hours via Royal Mail 24, free on orders over £25.