Retatrutide 20 mg

Triple Hormone Receptor Agonist · Weight Management / Rev. 01 / 2026

GLP-1 / GIP / Glucagon triple agonist • Subcutaneous

A clinician’s reference for reconstitution, dosing, administration, storage, and side effect management of Retatrutide lyophilized 20 mg vials. For research and educational use.

§ 00

Compound Data Card

CompoundRetatrutide (LY3437943)

Vial Size20 mg, lyophilized

RouteSubcutaneous (SC)

Half-life≈ 6 days

Typical Cycle24–48 weeks

Solution ColorClear, colorless

§ 01

Reconstitution

Use bacteriostatic water (BAC water) for reconstitution.
Inject slowly down the inner wall of the vial — do not spray directly onto the powder.
Roll the vial gently between your palms. Do not shake.
Refrigerate immediately. Use within 28 days.

20 mg ÷ 2.0 mL BAC water = 10 mg/mL

Target Dose	Volume	U-100 Units	Notes
1 mg	0.10 mL	10 units	Starting dose (Week 1–4)
2 mg	0.20 mL	20 units	Escalation (Week 5–8)
4 mg	0.40 mL	40 units	Escalation (Week 9–12)
8 mg	0.80 mL	80 units	Maintenance low
12 mg	1.20 mL	120 units*	Maintenance full (*use 1 mL syringe)

§ 02

Dosing Protocol

1Initiation

Week 1–4

1 mg weekly. Allows GI adaptation and baseline tolerance assessment.

1 mg / week

2Escalation

Week 5–12

2 mg weekly (wk 5–8), then 4 mg weekly (wk 9–12). Step up every 4 weeks if tolerated.

2–4 mg / week

3Maintenance

Week 13–24+

8 mg weekly, adjusted based on response. May increase to 12 mg for long-term maintenance (wk 24+).

8–12 mg / week

Inject once weekly, same day each week, evening preferred. Do not double-dose if a dose is missed — resume at the next scheduled day.

§ 03

Administration

Prepare

Wash hands thoroughly. Gather reconstituted vial, 1 mL syringe, alcohol swabs, and sharps container.

Swab

Wipe the vial stopper with an alcohol swab. Clean the injection site (abdomen, thigh, or upper arm).

Draw

Invert the vial and withdraw the prescribed dose using the dosing table above.

Inject

Pinch skin fold at the site. Insert needle at 45–90°. Inject slowly and steadily.

Rotate

Alternate injection sites weekly. Avoid the same spot within 7 days to reduce irritation.

Log

Record date, dose, injection site, and any side effects. Track weekly weight for progress monitoring.

§ 04

Storage & Handling

Storage

Lyophilized: 2–8°C (refrigerator), protect from light
Reconstituted: 2–8°C, use within 28 days
Caution: Never freeze reconstituted solution

Solution Checks

Solution should be clear and colorless
Discard if particulates, cloudiness, or discoloration appear
Label the vial with reconstitution date

§ 05

Side Effect Management

Most side effects are dose-dependent and tend to resolve within 2–3 weeks at each dose level. The phased escalation protocol above is designed to minimize gastrointestinal impact. Communicate any persistent symptoms to your healthcare provider.

Nausea (Most Common)

Eat smaller, more frequent meals
Avoid fatty or greasy foods
Ginger tea or ginger supplements may help

Reduced Appetite

Expected therapeutic effect
Ensure minimum nutrition intake (protein priority)
Stay hydrated — aim for 2–3 L water daily

Injection Site Reactions

Rotate injection sites each week
Apply ice before injection to reduce discomfort
Allow solution to reach room temperature before use

GI Discomfort

Usually resolves within 2–3 weeks per dose level
Slow dose escalation if symptoms persist
Consult provider if symptoms are severe or prolonged

§ 06

Safety & Regulatory

Important Notice

Retatrutide is not FDA-approved for weight loss or any therapeutic indication. It is supplied as a research peptide. Contraindicated in patients with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN2). Monitor blood glucose closely if diabetic. Not intended for pregnant or breastfeeding women. Any use must be conducted under the supervision of a qualified, licensed healthcare provider. This guide does not constitute medical advice.