R3 as a shot, injection or pen: what forms are available?
"R3 injection," "R3 shot," "R3 pen"... R3, the nickname for retatrutide, is as intriguing for its form as for its results. Here's how it appears in clinical trials and on the market, and what distinguishes a vial from a pen. This page does not provide any injection protocol: retatrutide is not an approved medication.
Retatrutide R3 10 mg – €59.90R10 Pack with kit – €69.90
The essentials
- In clinical trials, retatrutide is administered by injection under the skin, once a week.
- No official pen is on the market: without marketing authorization, Eli Lilly does not sell any retatrutide pens (seeIs R3 a medicine?).
- Commercially, R3 is available as a bottle of lyophilized powder (research peptide) or in unofficial pens prepared by resellers.
- No tablet: retatrutide does not withstand digestion.
Why R3 is injected (and not swallowed)
Retatrutide is a peptide, a chain of 39 amino acids. If swallowed, it would be broken down by digestive enzymes like any other protein before it could have any effect: this is why it is not available in tablet form. It also carries a fatty acid chain that allows it to circulate in the blood for a long time: its half-life is approximately 6 days, which explains the weekly dosing schedule used in the trials.
Does the R3 pen exist?
No official pen.The injection pens used for other molecules (Ozempic, Wegovy, Mounjaro) are authorized medications manufactured by pharmaceutical companies. For retatrutide, nothing of the sort exists until it is authorized.
The "R3 pens" sold online are therefore pens prepared by resellers, using retatrutide powder reconstituted into a solution. Before buying one, you should know that:
- the content isalready in solution, a form less stable than freeze-dried powder;
- there israrely a certificate of analysis specific to the pen: the actual concentration cannot be verified;
- The preparation date and the cold chain during transport are rarely indicated.
Freeze-dried bottle or pen: the differences
| Form | Content | Stability | Quality control |
|---|---|---|---|
| Freeze-dried bottle(10, 20 mg…) | Dry powder, to be dissolved | The most stable: it can be kept refrigerated before reconstitution. | Batch analysis certificate available (purity, measured quantity) |
| Pen prepared by a retailer | Solution already reconstituted | Limited duration from the start of preparation | Rarely a pen-specific certificate |
| "R3" tablet or capsule | Does not exist | — | This is not retatrutide |
For a laboratory, the lyophilized vial remains the reference form: it is the only one whose contents can be verified batch by batch. Our reports are published on the pagecertificates of analysis.
Laboratory equipment associated with a bottle
A lyophilized vial is reconstituted with bacteriostatic water and a reconstitution syringe; graduated syringes are then used for sampling, and swabs to disinfect the stoppers. Reconstitution and storage are detailed on our bacteriostatic water and retatrutide pages.
Our formats and prices
| Product | Content | Price |
|---|---|---|
| Retatrutide R3 10 mg | 1 lyophilized vial 10 mg | 59,90 € |
| Retatrutide R3 20 mg | 1 lyophilized vial 20 mg | 99,90 € |
| R10 Pack | Retatrutide 10 mg + bacteriostatic water, syringes, swabs | 69,90 € |
| R20 Pack | Retatrutide 20 mg + reconstitution kit | 109,90 € |
| Reconstitution Pack | Bacteriostatic water 3 ml, syringes, gloves, swabs (peptide-free) | 14,90 € |
| Bacteriostatic water 3 ml | 1 bottle, benzyl alcohol 0.9% | 5,00 € |
Each batch is blind-analyzed by Janoshik (purity and quantity measured), report verifiable with its key. Delivery €10, shipped from the European Union.
Retatrutide R3 10 mg – €59.90Retatrutide R3 20 mg – €99.90
Frequently Asked Questions
Is R3 taken by injection?
In clinical trials, retatrutide is administered by subcutaneous injection once a week. It is not available in any other form. Because retatrutide is not an approved medication, we do not provide any injection protocols.
Is there an official R3 pen?
No. Without marketing authorization, Eli Lilly does not manufacture or sell any retatrutide pens. Pens sold online are prepared by resellers.
How good are the R3 pens sold online?
Their contents are already in solution, making them less stable than powder, and they rarely have a pen-specific certificate of analysis: the actual concentration cannot be verified. The lyophilized vial with a batch analysis report remains the most controllable form.
Why is R3 not available in tablet form?
Because it's a peptide: if swallowed, it would be broken down by digestion before it could have any effect. The Eli Lilly tablet in question, orforglipron, is a different molecule.
How to store a bottle of R3?
As a freeze-dried powder: store in the refrigerator (2 to 8 °C), protected from light, or in the freezer for long-term storage. Once reconstituted: store in the refrigerator for approximately 4 weeks, without refreezing.
Sources: Jastreboff A.M. et al., N Engl J Med 2023 (phase 2); Eli Lilly press releases (TRIUMPH program, 2026). MyPeptide products are intended exclusively for scientific laboratory research.