Frequently Asked
Questions

Retatrutide is a next-generation synthetic peptide compound — a triple hormone receptor agonist that simultaneously activates three key metabolic receptors: GLP-1 (glucagon-like peptide-1), GIP (glucose-dependent insulinotropic polypeptide), and glucagon. This triple-receptor action distinguishes it from earlier weight-management compounds and has generated significant clinical interest.

Developed by Eli Lilly, retatrutide works by mimicking gut-derived hormones that regulate appetite, insulin secretion, and energy expenditure — targeting multiple metabolic pathways at once. Early Phase 2 trial data published in the New England Journal of Medicine demonstrated substantial weight reduction in trial participants.

As a peptide, retatrutide is a short chain of amino acids engineered to bind to and activate three specific hormone receptors in the body. Peptides are naturally occurring biological molecules — and synthetic peptides like retatrutide are designed to closely mimic or enhance the action of the body’s own hormonal signals.

The three receptors retatrutide targets each play distinct metabolic roles:

• GLP-1 receptor: Reduces appetite, slows gastric emptying, and stimulates insulin secretion in response to food.
• GIP receptor: Enhances insulin secretion and may improve fat metabolism and energy storage regulation.
• Glucagon receptor: Increases energy expenditure and promotes fat burning — a mechanism not activated by GLP-1-only compounds.

The combination of all three pathways is what gives retatrutide its potency as an investigational metabolic therapy. Learn more about peptide science via the NHS medicines resource.

Retatrutide is being clinically investigated across several overlapping areas of metabolic health. The primary areas under study include:

• Obesity and weight management: Phase 2 data has shown significant body weight reductions in obese participants, making it one of the most investigated compounds in this space.
• Type 2 diabetes: Its GLP-1 and GIP activity supports glycaemic control through improved insulin secretion and reduced post-meal glucose spikes.
• Non-alcoholic fatty liver disease (NAFLD/MASH): The glucagon receptor component may contribute to reducing hepatic fat accumulation.
• Cardiovascular risk reduction: As a metabolic therapy, retatrutide is being assessed for downstream cardiovascular benefits associated with weight loss and improved glycaemic control.

Alluvi retatrutide refers to the retatrutide formulations supplied through Alluvi Health Care — a UK-based licensed online pharmacy. Alluvi currently offers retatrutide in two dosage presentations:

• Retatrutide 20mg — for patients beginning or maintaining a supervised protocol
• Retatrutide 40mg — for patients progressing under clinician guidance

All Alluvi products are sourced from verified, regulated pharmaceutical supply chains and dispensed exclusively by GPhC-registered pharmacists. Every order undergoes pharmacist review before dispatch.

Retatrutide 20mg is the lower-dose formulation available from Alluvi Health Care. It is a prescription-only product intended for use within a clinician-supervised protocol.

As with all retatrutide formulations, the 20mg dose must only be prescribed and dispensed following a thorough clinical assessment by a qualified prescriber. Dosing strategy — including titration schedule and duration — is determined entirely by the supervising clinician based on the individual patient’s profile.

Retatrutide 40mg is the higher-dose formulation offered by Alluvi Health Care. As with the 20mg formulation, this is a prescription-only product and its use is determined entirely by the supervising prescriber.

Dose progression from a lower to a higher formulation is a clinical decision. Patients should not self-escalate dose without explicit prescriber approval. The GPhC and NHS provide guidance on safe use of prescription medicines.

Based on published Phase 2 clinical trial data, the most commonly reported side effects associated with retatrutide include:

• Nausea — particularly during dose escalation phases
• Vomiting and diarrhoea
• Decreased appetite (a pharmacological effect as well as a side effect)
• Constipation
• Injection-site reactions (erythema, bruising)
• Mild elevations in heart rate

Most gastrointestinal side effects are mild to moderate and transient, typically resolving as the body adjusts during titration. Serious adverse events should be reported immediately to your prescribing clinician and, where appropriate, to the MHRA Yellow Card scheme.

In clinical trials, retatrutide has been administered via subcutaneous injection — typically once weekly, similar to other GLP-1/GIP receptor agonists such as semaglutide and tirzepatide. Subcutaneous injections are given into the fatty tissue beneath the skin, commonly in the abdomen, thigh, or upper arm.

Administration technique, injection site rotation, and full protocol instructions must always be provided and supervised by a qualified prescriber or trained healthcare professional. Patients should never self-administer without proper clinical instruction and training.

Peptide compounds including retatrutide are temperature-sensitive and must be handled with care. General storage guidance applicable to peptide injectables includes:

• Store in a refrigerator at 2°C–8°C when not in use
• Protect from direct light and heat
• Do not freeze unless specifically indicated in product instructions
• Keep out of reach of children at all times
• Check expiry date before each use
• Follow all product-specific storage instructions provided at dispensing

All temperature-sensitive products dispatched by Alluvi Health Care are handled and shipped with appropriate cold-chain packaging in line with GPhC standards.

Ordering from Alluvi Health Care is straightforward. You can browse all available products — including retatrutide 20mg and retatrutide 40mg — directly through our online shop.

Prescription-only products require a valid prescription from a registered UK prescriber. Our pharmacy team will verify all prescription documentation before processing and dispatching any prescription order. Once verified, orders are dispatched with tracked delivery and full confirmation sent to your registered email address.

Alluvi Health Care offers tracked standard and express delivery options on eligible orders. All orders are dispatched from our UK-based pharmacy with full tracking information provided at the point of dispatch.

• Standard delivery: Estimated 2–3 working days
• Express delivery: Next working day dispatch available on eligible orders
• Cold-chain packaging: Automatically applied to temperature-sensitive products

For full delivery terms, visit our delivery information page. For any delivery queries, contact support@alluvishealthscare.uk.

Alluvi Health Care offers a full money-back guarantee on any product that arrives damaged, incorrectly dispensed, expired, or not as described. We are committed to resolving all refund requests within 3 working days of receipt.

Due to legal requirements governing pharmaceutical products, dispensed prescription medicines cannot be returned once dispensed — except where a product fault is identified. This is a regulatory requirement under UK law, not a commercial decision.

Full details, including eligibility criteria and step-by-step claim instructions, are available on our dedicated Refund & Returns Policy page.

This is one of the most searched questions in metabolic medicine right now, and the honest answer is: it depends on the individual patient and what clinical evidence is available at the time of prescribing.

Here is what we currently know from published data:

Tirzepatide (marketed as Mounjaro) is currently approved and available for prescription. Retatrutide has shown greater weight reduction in early trials due to its additional glucagon receptor activity, but long-term safety data is still being accumulated.

No compound is universally “better” — a prescribing clinician will assess your complete health profile, comorbidities, and treatment history before recommending any therapy. The NHS medicines resource and NICE guidelines are authoritative sources for approved therapies.

Semaglutide (Ozempic for diabetes, Wegovy for weight management) is a single GLP-1 receptor agonist — widely prescribed and well-evidenced. Retatrutide adds GIP and glucagon receptor activation on top of GLP-1, representing a step up in mechanistic complexity.

• Semaglutide: Single target (GLP-1), approved, established long-term safety profile, widely available.
• Retatrutide: Triple target (GLP-1 + GIP + Glucagon), currently in trials, early data suggests superior weight reduction but long-term outcomes are not yet established.

For patients who have not responded adequately to semaglutide, tirzepatide, or other GLP-1 therapies, retatrutide may — when and if approved — represent an advancement. However, this is a clinical decision only. Refer to NICE and your prescriber for current treatment pathways.

As of 2026, retatrutide is not available at Superdrug, Boots, Lloyds Pharmacy, or any other UK high-street or online pharmacy for standard patient dispensing — because it has not yet received full regulatory approval from the MHRA for routine clinical use.

High-street and online pharmacies including Superdrug can only dispense medicines that have received a valid marketing authorisation. Retatrutide does not yet hold this status in the UK.

Alluvi Health Care operates as a specialist licensed pharmacy. For the most current information on product availability, visit our shop or our homepage. Always verify any pharmacy’s GPhC registration before placing an order via the GPhC pharmacy register.