Weight

GLP-3 (Retatrutide)

5.0(1 review)

$54–$550

Prices checked 1 hour ago

Compare vendor offers for GLP-3 (Retatrutide), including price, dose, and purity.

Peptide Mind's top pick

Chosen on COA purity, third-party testing, and service, no paid placements.

Protide Health

99.69% COA|5.0|In stock

Buy now at Protide Health Compared across 4 vendors

At a glance · 4 vendors, 21 offers

Avg. vendor rating

4.2

Third-party tested

4/4

COA per batch

3/4

Offers in stock

19 of 21

COA purity range

99.49–99.991%

Ships from

4 of 4 vendors third-party tested, COA purity 99.49–99.991% across published labs. Prices re-checked 1 hour ago.

As seen on

Where to buy GLP-3 (Retatrutide) online

We compare GLP-3 (Retatrutide) offers across vetted research vendors so you can buy with confidence. Every price above is pulled from a verified, in-stock listing — here's what to look for before you check out.

Compare vendors on price-per-mg rather than sticker price, and confirm a third-party Certificate of Analysis (COA) is publicly available before you buy. The comparison table above flags self-tested-only results and account-required vendors so you can filter those out first.

Stick to vendors with no unresolved legal issues or community warnings, and check that stock and pricing were verified recently — the "last checked" date on each listing tells you exactly when. Products listed here are intended strictly for laboratory research use.

GLP-3 (Retatrutide) Price Comparison

Compare GLP-3 (Retatrutide) prices across every verified vendor and supplier, ranked by price, purity, and buyer-rated trust. Use the tabs to filter by size.

Prices last checked Aug 6

Vendor	Rating	Stock	Purity	Value	Price
Protide Health protidehealth.com	5.0	In stock	99.69% COA	Good	$145.00
Modern Aminos modernaminos.com	3.0	In stock	No purity reported	Below average	$94.00
Amino USA aminousa.com	4.3	In stock	No purity reported	Below average	$115.00
Prime Peptides primepeptides.co	4.6	In stock	No purity reported	Below average	$120.00

Protide Health

protidehealth.com

Visit Protide Health

Value: Good
Price: $145.00
Last checked: 1h ago
Rating: 5.0
Stock: In stock
Purity: 99.69% COA
Verified
Community signal: Endorsed
Reddit mentions: 129

Modern Aminos

modernaminos.com

Visit Modern Aminos

Value: Below average
Price: $94.00
Last checked: 1h ago
Rating: 3.0
Stock: In stock
Purity: No purity reported
Verified
Community signal: Flagged
Reddit mentions: 0

Amino USA

aminousa.com

Visit Amino USA

Value: Below average
Price: $115.00
Last checked: 1h ago
Rating: 4.3
Stock: In stock
Purity: No purity reported
Verified
Community signal: Not endorsed
Reddit mentions: 0

Prime Peptides

primepeptides.co

Visit Prime Peptides

Value: Below average
Price: $120.00
Last checked: 1h ago
Rating: 4.6
Stock: In stock
Purity: No purity reported
Verified
Community signal: Flagged
Reddit mentions: 0

How to Store GLP-3 (Retatrutide)

Freeze the dry powder, protected from light. Once mixed with liquid, refrigerate and use within about a month, and don't freeze it once mixed.

Lyophilized Storage

-20°C or below, protected from light.

Reconstituted Storage

2–8°C for up to 28 days.

Handling Notes

Do not freeze the reconstituted solution.

Read the full storage guide

A smartphone displaying a "Storage Guide" for peptides, indicating a safe storage temperature range of 2–8°C, with warnings to keep away from light, heat, and freezing. The background is light blue, and additional tips on protecting the peptides are visible below the temperature range.

Compare GLP-3 (Retatrutide) Vendors

See which vendors and suppliers are trusted for GLP-3 (Retatrutide) — compare price, purity, and buyer trust signals side by side to find the best one to buy from.

Protide Health is a USA-based research peptide supplier operating from Las Vegas, Nevada, offering HPLC-MS third-party verified compounds at 99%+ analytical purity with public batch-specific certificates of analysis. The company sources from ISO 9001:2015 certified, GMP-compliant manufacturing facilities and is known as a transparent domestic supplier for in vitro laboratory research.

Visit store

Sizes

Overview

Value: Good
Price: $145.00
Rating: 5.0(149)
Verified
Community signal: Endorsed
Reddit mentions: 129

Testing & Purity

Purity: 99.69% COA
Testing: Third-party tested: yesCOA per batch: yesMass spectrometry: yes

Ratings

Purity accuracy: 5.0
Price value: 4.9
Shipping speed: 5.0
Packaging: 4.9
Customer service: 5.0

Buying

In stock
Account required
Payments: Card: yesPayment apps: noCrypto: noBank transfer: noOther: no
Ships to: United States
Last checked: 1h ago

Modern Aminos is a US research-use-only (RUO) peptide vendor requiring account login to view its full catalog. It advertises a multi-stage QA program with QR-linked, per-batch Certificates of Analysis, but an independent vendor reviewer (VialVerdict) reports that HPLC/COA data is actually available on request only and not standard practice — directly contradicting the vendor's own marketing. Independent lab aggregator Finnrick.com has only tested 5 samples (one product, Retatrutide), with 1 of 5 failing purity/fill standards.

Visit store

Sizes

Overview

Value: Below average
Price: $94.00
Rating: 3.0
Verified
Community signal: Flagged
Reddit mentions: 0

Testing & Purity

Purity: No purity reported
Testing: Third-party tested: noCOA per batch: noMass spectrometry: yes

Ratings

Purity accuracy: 1.0
Price value: 4.0
Shipping speed: 4.0
Packaging: 2.5
Customer service: 4.0

Buying

In stock
Account required
Payments: Card: yesPayment apps: yesCrypto: yesBank transfer: noOther: no
Ships to: United States
Last checked: 1h ago

Amino USA is a Houston, Texas-based research peptide vendor that supplies lyophilized peptides and bioregulators strictly for laboratory research purposes, partnering with third-party labs BioRegen and MZ Biolabs to verify purity and identity via HPLC-MS analysis.

Visit store

Sizes

Overview

Value: Below average
Price: $115.00
Rating: 4.3(18)
Verified
Community signal: Not endorsed
Reddit mentions: 0

Testing & Purity

Purity: No purity reported
Testing: Third-party tested: yesCOA per batch: yesMass spectrometry: yes

Ratings

Purity accuracy: 4.5
Price value: 4.0
Shipping speed: 4.2
Packaging: 4.3
Customer service: 4.1

Buying

In stock
Account required
Payments: Card: yesPayment apps: noCrypto: yesBank transfer: yesOther: no
Ships to: United States
Last checked: 1h ago

GLP-3 (Retatrutide) Dosage Guide for Weight LossGLP-3 (Retatrutide) Dosage Calculator

This is Retatrutide, an experimental medication that activates three different gut hormone pathways at once. Doses are raised slowly over time, a process called titration, with each step held for four weeks. In the Phase 3 TRIUMPH trials, everyone starts at 2 mg per week and steps up from there: 2 → 4 → 6 → 9 → 12 mg. Earlier trials found that starting at 2 mg rather than 4 mg caused fewer stomach side effects while producing the same weight loss at 48 weeks. Some people take much smaller 'microdoses,' often around 0.5 mg per week, to reduce side effects further. Going up gradually matters because most side effects, especially nausea and other stomach issues, appear right after a dose increase rather than at a steady dose.

Vial size

10 mg

Bacteriostatic water

2 mL

Dosing

2–12 mg (titrated)

Frequency

Weekly

Cycle

16-48 weeks

Benefit

Weight Loss

Explore calculators

Basic Dosage Calculator

Calculate peptide doses with our visual syringe guide.

Peptide per vial

Target research quantity

Bac water added

GLP-3 (Retatrutide) Dosage Guide for Weight LossGLP-3 (Retatrutide) Dosage Calculator

This is a microdose approach to Retatrutide (GLP-3). Instead of starting at the 2 mg used in clinical trials, microdosing protocols begin around 0.25 mg per week and step up every two to four weeks: 0.25 → 0.5 → 1 → 1.5 → 2 mg. Some people split the weekly amount into two injections, usually Monday and Thursday, which lowers the peak blood level by roughly 28% and is the usual explanation for less nausea. The reported upsides are milder nausea and stomach issues, steadier appetite control between doses, and a slower rate of loss that's easier to pair with holding onto muscle. None of this has been tested in trials, and lower doses do produce less weight loss, so it trades results for tolerability.

Vial size

10mg

Bacteriostatic water

3mL

Dosing

0.25–2 mg (titrated)

Frequency

Weekly

Cycle

16+ weeks

Benefit

Weight Loss

Explore calculators

Basic Dosage Calculator

Calculate peptide doses with our visual syringe guide.

Peptide per vial

Target research quantity

Bac water added

How to reconstitute GLP-3 (Retatrutide)

View guide

The materials you'll need and step-by-step instructions for safely mixing GLP-3 (Retatrutide) with bacteriostatic water.

Materials needed

Your GLP-3 (Retatrutide) vial (lyophilized)

Alcohol swabs

Bacteriostatic sterile water

3 mL syringes (Luer Lock tip)

25G or 27G needles (Luer Lock). Other gauges may also be acceptable.

Sharps container (optional)

Remove the caps

Remove the caps from both your GLP-3 (Retatrutide) vial and your bacteriostatic water vial.

Sanitize the rubber stoppers

Wipe down the rubber stoppers on both vials with alcohol swabs and let them dry for about 3 minutes.

Attach the needle

Take your 3 mL syringe and needle. Twist the needle's plastic hub into the Luer Lock tip on the syringe to secure it.

Draw the bac water

Pull back on the plunger to draw your desired volume of bacteriostatic water. If you overfill, just push the excess back in until you reach the right marker on the syringe.

How much bac water? GLP-3 (Retatrutide) typically comes in a 10 mg vial. We recommend 2 mL of bacteriostatic water, though anywhere between 1 mL and 3 mL is acceptable. For larger vials you can use up to 5 mL — more bac water makes microdosing easier, but insulin needles usually max out at 1 mL per injection. That means a lot of bac water might force you into multiple injections to hit your target dose. Unless you're microdosing, 2 mL per vial is a solid rule of thumb.

Insert the needle into the GLP-3 (Retatrutide) vial

With the bac water in your syringe, insert the needle into the GLP-3 (Retatrutide) vial at a slight angle to avoid pressure buildup.

Use a thin needle: Stick to 25G or higher to avoid damaging the rubber stopper. Higher gauge means a thinner needle.

Release the water gently

Let the water run gently down the side of the vial. Don't inject it forcefully.

Heads up: Sometimes the plunger pushes itself in as soon as the needle enters the vial. Hold the plunger back so you have full control over how fast the bac water enters.

Swirl to dissolve

Avoid shaking. Gently swirl, flip, and roll the vial to dissolve the powder.

Be patient: This usually takes 2 to 5 minutes of consistent swirling, mixing in a circular motion, and gently flipping the vial up and down. The water needs to run through the powder many times to fully dissolve it. Don't shake or get aggressive with it.

Check for full dissolution

The solution should be clear with no visible particles. If it's cloudy or clumpy, wait a minute and repeat the swirling step.

Cap, dispose, and store

Once you're done, cap the needle and dispose of it (ideally in a sharps container). Store the reconstituted GLP-3 (Retatrutide) vial in the fridge whenever it's not in use. It will stay good for approximately 30 days.

How We Rank Offers

We don't just sort by price. Here's how each offer's rating actually gets calculated.

Compared Apples to Apples

We score price per mg against other offers of the same dose size, not the sticker price, so a bigger vial doesn't look like a worse deal than it is.

Price Is Only Part of the Score

We weigh price-per-mg alongside vendor rating, COA purity, and account requirements, so a cheap offer from an unproven vendor won't outrank a fair price from a trusted one.

Trust Gates the Top Ratings

A sub-4.0-rated vendor can't earn "Great value," and missing third-party purity data caps an offer out of "Good" or "Great." No price is low enough to buy around it.

Vendor Trust Signals

We don't sell GLP-3 (Retatrutide) ourselves — every vendor below is vetted and rated independently before being listed here.

Protide Health — 5.0/5 (149 reviews)

Public, third-party tested COAs on every batch, based in US, account required to view pricing.

Amino USA — 4.3/5 (18 reviews)

Public, third-party tested COAs on every batch, based in US, account required to view pricing.

Modern Aminos — 3.0/5

Based in US, account required to view pricing.

Compare all vendor reviews

GLP-3 (Retatrutide) Buying FAQ

Straight answers on legality, pricing, and vendor vetting before you buy. For research reference only.

Retatrutide (sometimes referred to informally as "GLP-3") is an investigational triple agonist that activates the GLP-1, GIP, and glucagon receptors simultaneously, distinguishing it from single- or dual-agonist peptides like semaglutide and tirzepatide. It remains an investigational compound and is not FDA-approved; on this site it is listed strictly for research purposes, not for human or animal consumption.

In published clinical research, retatrutide is typically escalated in a stepwise fashion (e.g., roughly 2 mg increments every 4 weeks) up to maintenance doses in the 4–12 mg range, dosed once weekly. "Microdosing" refers to using amounts well below these clinical-trial doses; this approach is popular in search interest but is not standardized or validated in published literature, so protocols vary widely by source. Always consult our dosage calculator and microdosing protocol page for reference figures, and treat all dosing information as informational only.

Lyophilized (powder) retatrutide is generally reconstituted with bacteriostatic water using a peptide reconstitution calculator to determine the correct dilution for a target concentration. Once reconstituted, solutions are typically kept refrigerated (2–8°C) and used within about 28 days, while unreconstituted lyophilized powder is more stable and should also be stored refrigerated or frozen, protected from light. Repeated freeze-thaw cycles after reconstitution are generally avoided as they can degrade peptide integrity.

In published Phase 2/3 trial data, the most commonly reported effects were gastrointestinal — nausea, diarrhea, constipation, and dizziness — occurring mainly during dose-escalation and generally described as mild to moderate. Serious adverse event rates in trials were comparable to placebo, but this reflects a controlled clinical setting; unregulated research-chemical products carry additional, unquantified risks related to purity and sterility.

Semaglutide is a single GLP-1 receptor agonist, tirzepatide is a dual GLP-1/GIP agonist, and retatrutide adds a third mechanism (glucagon receptor agonism), which is why it's colloquially nicknamed "GLP-3" or the "triple G" agonist. Cross-trial comparisons (not head-to-head studies) have associated retatrutide with the largest average weight reductions of the three in published data, but direct comparative trials are limited and each compound has a different data maturity and regulatory status.