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Diluent UK Research Peptides
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Buy Peptides UK

Buy research peptides in the UK, from stock held here: vials, pens, capsules and nasal sprays, each at ≥99% purity, with a certificate of analysis on request. Orders before 2pm leave the same day.

Everything listed here is already sitting in British stock at Diluent, not sourced after you buy it. That is why a weekday order received before 2pm can leave the same day on a tracked service, with no border to cross, so no customs clearance and no import charge.

The range is organised by research area, and each compound is offered in one or more sizes and formats. Every size carries its unit price and its price per milligram. Each batch measures ≥99% by HPLC, and a certificate of analysis for your order is available on request. How ordering works.

Metabolic & GLP-1

Open shelf →
Retatrutide Retatrutide
£28.99
Tirzepatide Tirzepatide
£25.99
MOTS-c MOTS-c
£15.99
SLU-PP-332 SLU-PP-332
£29.99
Semaglutide Semaglutide
£9.99
AOD-9604 AOD-9604
£17.99
5-Amino-1MQ 5-Amino-1MQ
£35.99
Cagrilintide Cagrilintide
£38.99
Tesofensine Tesofensine
500mcg £53.99

Repair & Recovery

Open shelf →
BPC-157 BPC-157
£19.99
TB-500 TB-500
10mg £32.99
BPC-157 + TB-500 BPC-157 + TB-500
£27.99
KPV KPV
£21.99
Thymosin Alpha-1 Thymosin Alpha-1
£62.99
ARA-290 ARA-290
10mg £61.99
VIP VIP
10mg £26.99

Growth Hormone Axis

Open shelf →
Ipamorelin Ipamorelin
£19.99
CJC-1295 DAC CJC-1295 DAC
2mg £18.99
Tesamorelin Tesamorelin
10mg £31.99
CJC-1295 + Ipamorelin CJC-1295 + Ipamorelin
£59.99

Skin & Pigment

Open shelf →
GHK-Cu GHK-Cu
£24.99
Melanotan 2 Melanotan 2
nasal spray £24.99
GLOW GLOW
£55.99
KLOW KLOW
£71.99

Cognitive & Sleep

Open shelf →
Semax Semax
£18.99
DSIP DSIP
5mg £19.99

Cellular & Longevity

Open shelf →
NAD+ NAD+
500mg £33.99
SS-31 SS-31
£26.99
Methylene Blue Methylene Blue
10mg £44.99

Reproductive & Libido

Open shelf →
Kisspeptin-10 Kisspeptin-10
£17.99
PT-141 PT-141
10mg £20.99

Stacks, Blends & Kits

Open shelf →
BPC-157 Starter Kit BPC-157 Starter Kit
10mg £37.99
Dual Agonist Stack Dual Agonist Stack
stack £110.99
GH Stack GH Stack
stack £40.99
Metabolic Stack Metabolic Stack
stack £99.99
Pen Starter Kit Pen Starter Kit
40mg £121.99
Recomp Stack Recomp Stack
stack £68.99
Recovery Stack Recovery Stack
stack £69.99
Retatrutide + Cagrilintide Blend Retatrutide + Cagrilintide Blend
10mg/5mg £70.99
Retatrutide Starter Kit Retatrutide Starter Kit
10mg £57.99
Semaglutide + Cagrilintide Blend Semaglutide + Cagrilintide Blend
5mg/5mg £46.99
Skin + Repair Stack Skin + Repair Stack
stack £42.99
Sleep + Recovery Stack Sleep + Recovery Stack
stack £38.99
Tirzepatide + Cagrilintide Blend Tirzepatide + Cagrilintide Blend
10mg/5mg £67.99
Tirzepatide Starter Kit Tirzepatide Starter Kit
10mg £53.99
Wolverine Stack Wolverine Stack
stack £49.99

Lab Supplies

Open shelf →
Bacteriostatic Water Bacteriostatic Water
£5.49
Alcohol Swabs Alcohol Swabs
100 pack £3.99
Insulin Syringes 1ml 30G Insulin Syringes 1ml 30G
100 pack £9.99
Pen Needles 32G Pen Needles 32G
100 pack £8.99

How to choose a peptide supplier in the UK

A few questions are worth putting to any seller, us included, and every one can be answered before you pay. The guide to checking a UK peptide supplier works through each in turn, and it is open about the cases where we are not the right shop for you.

The questions, and our published answers
QuestionOur answer
Where is it sent from?A UK address. Nothing crosses a border on the way, which rules out a customs stage and any import charge.
How pure is it, and how is that measured?≥99%, by HPLC, and the figure is printed on every label.
Is a certificate available?Yes. Ask for one and it is sent for the stock you actually received, not for some other run.
Is pricing per vial or per milligram?Both are shown. A rate per milligram sits beside every size, so any two sizes can be compared.
What turns up?Freeze-dried powder in a sealed vial, except where a compound comes in pen, capsule or spray form.
What is it sold for?Laboratory research and nothing else. We are not a pharmacy, nothing here is a licensed medicine, and no dosage or protocol guidance is published.

What are research peptides?

A peptide is a short chain of amino acids linked by peptide bonds. Once a chain runs past about fifty residues it is normally called a protein instead, a boundary set by convention and not by any rule. At three residues, KPV is the shortest we sell; Thymosin Alpha-1, at twenty-eight, is the longest.

Not everything sold under this heading is a peptide, and where something is not, we say so plainly. NAD+, for one, is a coenzyme built from two nucleotides. 5-Amino-1MQ and SLU-PP-332 are both small molecules, and Methylene blue belongs to the phenothiazine family of dyes. Their place in this range comes from the research literature, which groups them with peptides, rather than from any shared chemistry.

Here, "research" is the name of a supply category rather than a marketing term. It covers unlicensed compounds supplied for laboratory work. None holds a UK marketing authorisation or is a licensed medicine, and none is supplied for human or veterinary use.

Which formats are research peptides sold in?

Four formats compared, from delivery to storage
FormatWhat you receivePreparationStorage
Lyophilised vialVacuum-sealed, freeze-dried powderReconstituted with bacteriostatic waterMonths in the fridge, years frozen
PenPre-filled solutionNoneInto the fridge on arrival
CapsulesSolid, finished formNoneCool, dry, sealed
Nasal spraySolution, ready as suppliedNoneInto the fridge on arrival

The vial dominates the range for a chemical reason, not a commercial one. Water drives the reactions that break a peptide down, and freeze-drying removes it; without that step a peptide could not be sent by post at all. Pens, capsules and sprays are offered where doing without the preparation step earns its place.

Buying research peptides in the UK: how does it work?

Start with a seller whose stock is already inside the UK, because that alone is the gap between delivery in two days and delivery in three weeks. A parcel sent from overseas must clear customs, can collect an import charge and a handling fee en route, and may be held or seized entirely. Orders placed here never approach a border.

What to expect from an order
AccountNot required; checkout asks for a name, address and email
DispatchWeekday orders before 2pm go that day, later ones the next
DeliveryUK addresses only, tracked. £4.95, or free over £75
PackagingAn unmarked outer box, with no hint of the contents
PaymentDetails sent by email once you order; no charge is taken on the site
ReturnsWithin 14 days, if the seal is unbroken

The full ordering guide →

What has published research on these compounds examined?

It varies widely, and the evidence is uneven. Human trials exist for a handful of these compounds; most have had none. Below, by research area, is the published work along with the model each study used:

Published evidence, research area by research area
Research areaBest-supported published work
Metabolic and GLP-1 Semaglutide and tirzepatide have phase 3 human trials, one of them head-to-head (doi:10.1056/NEJMoa2416394). Retatrutide has a published phase 2 trial (PMID 37366315).
Repair and recovery Human trials of BPC-157 exist in gastrointestinal medicine (PMID 17186181); everything else on this shelf rests on rodent and in-vitro studies.
Growth hormone axis Tesamorelin: a meta-analysis pooling five randomised controlled trials (PMID 41545261). CJC-1295: tested in healthy adults in a randomised placebo-controlled trial (PMID 16352683).
Skin and pigment The GHK-Cu record is reviews and gene-expression studies (PMID 29986520), not clinical trials.
Cognitive and sleep Semax: rat work on BDNF (PMID 14556513) and a non-randomised study of 110 patients.
Reproductive Kisspeptin-10 has been studied in healthy human volunteers (PMID 21976724).

Every compound page carries a reference list grouped by study model, with a link to each paper so it can be read in full. If the published record for a compound is thin, that page states it.

This summarises what the studies set out to investigate; it is not a claim that anything has an effect in a person. Nowhere on the site is there a dose, protocol, route or frequency.

How do you prepare research peptides?

The vial arrives as dry powder and is reconstituted with bacteriostatic water: sterile water containing benzyl alcohol, a preservative that allows the vial to be entered repeatedly. The volume you add sets the concentration and nothing else; the amount in the vial stays exactly as labelled.

A 10mg vial at four volumes
Water addedConcentration
1 ml10 mg/ml
2 ml5 mg/ml
3 ml3.33 mg/ml
5 ml2 mg/ml

Each product page repeats this table using that compound's own sizes. A few points of technique: bring a cold vial up to room temperature, wipe the stopper, run the water down the inside of the glass rather than onto the powder, and swirl gently instead of shaking. Foaming is the protein denaturing, and it shows.

How do you store research peptides?

Typical shelf life of a lyophilised peptide
ConditionTypical life
Frozen at −20 °C, sealedYears
Refrigerated at 2–8 °C, sealedMonths
Room temperature, sealedWeeks: enough for transit, too short for storage
Refrigerated after reconstitutionWeeks, with about four the usual working figure
Frozen after reconstitutionAvoid, as ice crystals damage the peptide

Keeping a peptide cold and dry extends its life, while moisture, heat, light and agitation shorten it. Repeatedly taking it out of the fridge and putting it back does more harm than a warm shelf would, so pick one place and keep it there.

No compound sold here is a controlled drug, and each can lawfully be sold as laboratory material. It is unlawful, though, to sell or market them for people to take; that falls within the Human Medicines Regulations 2012. For that reason no page here gives a dose, protocol, route, frequency or medical claim, and an email request for one is refused in the same way.

A number of these molecules are also found in brand-name licensed medicines. In each case the authorisation attaches to the finished product alone, meaning one manufacturer, one formulation, one presentation and one approved use, and it does not travel with the molecule. Read the full terms.

Research use only. Diluent is not a pharmacy, and none of its compounds is a licensed medicine: everything is sold for laboratory research, with no dosage, protocol or administration guidance given. Not intended for human or veterinary use, or for use in food.

Questions about research peptides

Where can research peptides be bought in the UK?

From Diluent. The whole range is held on UK shelves, and an order received before 2pm on a working day is sent that day, tracked, in plain packaging. Because nothing comes in from abroad, there is no customs clearance to wait for, no import charge to pay and no hold-up at a border.

How pure are your research peptides?

Purity is ≥99%, measured by HPLC, and a certificate of analysis for the stock you receive can be requested.

When will my order be sent?

Before 2pm on a weekday, it is sent that day; after 2pm, at a weekend or on a bank holiday, it goes the next working day. Tracked delivery, UK addresses only.

Can you deliver outside the UK?

No. We deliver only to UK addresses, and a freight-forwarding address will not be accepted.

How much bacteriostatic water goes into a vial?

There is no fixed amount: the volume you choose determines the concentration. A 10mg vial with 2ml added gives 5 mg/ml, and with 1ml it gives 10 mg/ml. Every product page runs the same table for its own sizes.

What is the shelf life of a research peptide?

Freeze-dried in a sealed vial: years at −20 °C, months refrigerated and weeks at room temperature. After reconstitution and kept in the fridge, expect weeks rather than months, and do not freeze it once it is in solution.

Is dosage information published here?

No, and a request by email is answered the same way. Each product is an unlicensed research compound for laboratory use only. The site does give reconstitution arithmetic and storage conditions, since those describe a material and a solution, not what anyone should do with them.