Retatrutide 10mg vs 20mg vs 30mg: Which Vial Size Should You Buy? (UK 2026)
Research-grade retatrutide is usually sold in three vial sizes: 10mg, 20mg and 30mg. The peptide inside is the same — the difference is how much of it is in each vial. Picking the right size affects how much you pay per milligram, how concentrated your solution is after reconstitution, and how much material you have in solution at any one time. This guide walks through each factor so you can choose the right vial for your lab.
Quick answer: the 30mg vial is the best value per milligram, the 10mg vial is the lowest outlay and suits small or first-time projects, and the 20mg sits in the middle. For ongoing work, multi-packs bring the price per milligram down further.
Retatrutide Vial Sizes Compared
| Option | Price | Cost per mg | Best for |
|---|---|---|---|
| Retatrutide 10mg | £57.99 | £5.80 | Small or pilot projects |
| Retatrutide 20mg | £89.99 | £4.50 | Medium-length projects |
| Retatrutide 30mg | £109.99 | £3.67 | Best single-vial value |
| Retatrutide 30mg 3-Pack | £279.99 | £3.11 | Ongoing research |
| Retatrutide 30mg 10-Pack | £824.99 | £2.75 | Labs and group buys |
Every vial comes from a batch independently tested by Janoshik at 99.857% purity — you can verify the COA on the lab’s own website.
1. Cost per Milligram
The larger the vial, the cheaper each milligram becomes. Going from a single 10mg vial (£5.80/mg) to a single 30mg vial (£3.67/mg) cuts the cost per milligram by over a third. If your project will use more than 10mg in total, buying one 30mg vial is cheaper than buying three 10mg vials (£109.99 vs £173.97).
The 10mg vial still makes sense when you only need a small amount, want to evaluate a new batch before committing, or are running a short pilot.
2. Concentration After Reconstitution
Retatrutide is supplied as a lyophilised (freeze-dried) powder and must be reconstituted with bacteriostatic water before use. The concentration you end up with is simply the amount of peptide divided by the volume of water you add:
| Vial | + 1ml water | + 2ml water | + 3ml water |
|---|---|---|---|
| 10mg | 10mg/ml | 5mg/ml | 3.33mg/ml |
| 20mg | 20mg/ml | 10mg/ml | 6.67mg/ml |
| 30mg | 30mg/ml | 15mg/ml | 10mg/ml |
Higher-content vials give you a stronger solution for the same volume of water, which matters when your protocol needs small, precise volumes. Our free Peptide Reconstitution Calculator works out the exact concentration and volume for any vial size, and How to Reconstitute Research Peptides covers the full method.
3. Storage and How Fast You’ll Use It
This is the factor most people overlook. Unopened lyophilised vials are stable for a long time when kept at 2–8°C. Once reconstituted, the clock starts: a solution made with bacteriostatic water should be kept refrigerated and is generally used within about four weeks.
So the right size depends on how quickly your project will work through the material once it is in solution:
- Using it slowly? Several smaller vials can be better than one large one — you only reconstitute what you need and keep the rest as stable powder.
- Using it steadily? A 30mg vial gives the lowest cost per milligram and fewer vials to prepare.
- Running a longer project? A 30mg 3-pack gives you the best price while keeping two vials sealed until needed.
More detail in our guide to bacteriostatic water: how much to use and how long it lasts.
4. What Else You’ll Need
Each vial needs bacteriostatic water, syringes and alcohol swabs. The easiest way to get everything at once is the Retatrutide 30mg Research Bundle, which includes a 30mg vial, 10ml bacteriostatic water and a Starter Accessory Pack for £114.99 — £9.98 less than buying them separately. Browse all bundles and value packs.
Which Size Should You Choose?
- Choose 10mg if you want the lowest upfront cost, a small pilot quantity, or to try a new supplier’s batch first.
- Choose 20mg if 10mg won’t be enough but you don’t want a large amount in solution at once.
- Choose 30mg for the best value per milligram on a single vial.
- Choose a multi-pack for ongoing research — the 30mg 3-pack works out at £3.11/mg and the 10-pack at £2.75/mg.
View Retatrutide 10mg, 20mg and 30mg →
Frequently Asked Questions
Is the peptide different between 10mg, 20mg and 30mg vials?
No. It is the same retatrutide from the same tested batch — only the amount per vial changes.
Which retatrutide vial is the best value?
The 30mg vial is the best value single vial at £3.67 per mg. Multi-packs are cheaper still: £3.11 per mg for the 30mg 3-pack and £2.75 per mg for the 10-pack.
How much bacteriostatic water do I add to a retatrutide vial?
It depends on the concentration you need. Adding 2ml to a 10mg vial gives 5mg/ml; adding 3ml to a 30mg vial gives 10mg/ml. Use our Peptide Calculator to work out any combination.
How long does reconstituted retatrutide last?
Reconstituted with bacteriostatic water and kept at 2–8°C, it is generally used within about four weeks. Unopened lyophilised vials last much longer in the fridge.
Where can I buy retatrutide in the UK?
Revial Labs stocks retatrutide 10mg, 20mg and 30mg in the UK, independently tested by Janoshik at 99.857% purity, with same-day dispatch by Royal Mail Tracked on orders placed before 2pm on working days. See our Retatrutide UK guide for how to choose a reliable supplier.
This article is provided for educational and informational purposes for laboratory research professionals. All Revial Labs compounds are supplied strictly for in vitro laboratory research use only and are not for human or veterinary use.
