PHARMACIST-REVIEWED MEDICATION GUIDE
A clear UK guide to GLP-1 weight loss medicines, how they work, treatment options, side effects, safety checks, storage and pharmacy support.
All prescription weight-management medicines require assessment by a registered prescriber and regular clinical oversight. Iris Health dispenses valid prescriptions and does not prescribe.
PRESCRIPTION-ONLY TREATMENT
GLP-1-based weight-management medicines require an appropriate clinical assessment, a valid prescription and ongoing monitoring. Never start, stop or change a dose without guidance from the prescribing team.
GLP-1 EXPLAINED
GLP-1 receptor agonists are prescription medicines that mimic a hormone released by the gut after eating. They act on pathways involved in appetite, fullness, stomach emptying and blood-glucose regulation.
These medicines can promote earlier satiety and reduce appetite, supporting smaller portions.
Slower stomach emptying can help fullness last longer after meals.
In plain terms: the gut releases GLP-1 after eating. This signals the brain that the body is becoming full and tells the stomach to slow down. GLP-1 medicines keep that signal active for longer.
HOW THEY MAY HELP
IMPORTANT CONTEXT
Weight loss medicines work alongside dietary change and physical activity, not instead of them. Responses vary, and long-term decisions should be made with the prescriber.
Weight regain can occur after treatment stops. Discuss duration, dose changes and ongoing support with the prescribing healthcare professional.
UK TREATMENT OPTIONS
Common options include semaglutide, tirzepatide and orlistat. Availability, funding and suitability vary, and a clinical assessment is required before prescription medicines can be issued.
Orlistat reduces fat absorption and is available through prescription routes and, at lower strength, over the counter. Treatment options continue to evolve; ask a healthcare professional about individual suitability.
SAFE PRESCRIBING
Safe use depends on a thorough assessment before treatment, responsible dose decisions and regular monitoring.
The assessment considers more than BMI, including relevant conditions and treatment goals.
Contraindications, allergies and interactions with current medicines are reviewed.
The prescriber selects an appropriate starting dose and escalation schedule.
Effectiveness, tolerability, side effects and dose changes are monitored throughout treatment.
SAFETY CONSIDERATIONS
Suitability is individual. A registered prescriber must review contraindications, pregnancy status, allergies, medical history and current medicines before treatment begins.
STORAGE GUIDANCE
Wegovy and Mounjaro pens generally require refrigeration at 2–8°C before use and must not be frozen. Product-specific instructions can differ, so always follow the leaflet supplied with the exact pen.
When medication is delivered, refrigerate it promptly on receipt. If you are concerned about the parcel condition or temperature, contact the pharmacy before administering it.
Storage instructions can be product-specific. If you are unsure whether the medicine has been stored correctly, contact the pharmacy before using it.
SAFETY & MONITORING
Gastrointestinal effects are commonly reported, particularly early in treatment and after dose increases. They may improve as the body adjusts, but concerning symptoms require clinical advice.
The patient information leaflet is the authoritative source. Do not stop or change medication without guidance from the prescribing clinical team.
| Side effect | Reported frequency | General guidance |
|---|---|---|
| Nausea | Very common | Smaller meals may help; contact the clinical team if severe. |
| Diarrhoea | Very common | Maintain hydration and seek advice if persistent or severe. |
| Vomiting | Common | Seek advice if it prevents adequate food or fluid intake. |
| Constipation | Common | Discuss persistent symptoms with a pharmacist or prescriber. |
| Abdominal discomfort | Common | Seek advice if severe or accompanied by other symptoms. |
| Injection-site reactions | Common | Follow the administration guidance and rotate sites as advised. |
| Headache or fatigue | Less common | Contact the clinical team if significant or persistent. |
| Pancreatitis | Seek advice promptly | Stop treatment and obtain urgent medical advice as directed in the leaflet. |
| Gallbladder symptoms | Seek advice promptly | Discuss relevant symptoms with the clinical team promptly. |
Examples include severe or persistent abdominal pain, vomiting that prevents eating or drinking, signs of a severe allergic reaction, or any symptom the patient leaflet identifies as requiring immediate attention.
TREATMENT COMPARISON
Both are once-weekly injectable prescription weight-management medicines. The key difference is mechanism. Neither is universally better; the appropriate option depends on individual assessment and prescriber recommendation.
| Feature | Wegovy | Mounjaro |
|---|---|---|
| Active ingredient | Semaglutide | Tirzepatide |
| Mechanism | GLP-1 receptor agonist | Dual GLP-1 and GIP agonist |
| Administration | Weekly subcutaneous injection | Weekly subcutaneous injection |
| UK licensing | Licensed for weight management | Licensed for weight management |
| Prescription | Prescription-only | Prescription-only |
| Storage before use | 2–8°C; do not freeze | 2–8°C; do not freeze |
| Room-temperature limit | Below 30°C for up to 30 days | Below 30°C for up to 30 days |
| Clinical suitability | Prescriber assessment required | Prescriber assessment required |
Iris Health dispenses against valid prescriptions. Your prescriber determines which treatment, if any, is suitable for you.
WHY IRIS HEALTH
GLP-1 medicines need prescription verification, safe dispensing, appropriate temperature control and responsive pharmacy support.
A GPhC-registered specialist pharmacy with weight-management experience.
Every prescription reviewed before dispensing.
Temperature-controlled packaging selected for the medicine and transit time.
Delivery updates from dispatch to the eligible UK address.
Confidential, tamper-evident outer packaging.
Support for valid private prescriptions; confirm any NHS arrangements separately.
OUR COMMITMENT
Every order goes through verification and accuracy checks before it leaves the pharmacy.
GETTING STARTED
If a registered healthcare professional has issued a prescription, Iris Health can advise whether it can be accepted for specialist fulfilment.
Complete an appropriate clinical assessment with a registered prescriber.
The clinic or prescriber can send the prescription using an accepted route.
The pharmacist checks the prescription and safely dispenses the medicine.
Medication is packed for its storage requirements and dispatched using the confirmed service.
FREQUENTLY ASKED QUESTIONS
These answers provide general information only. Individual clinical questions should be directed to the prescribing healthcare professional.
They are prescription medicines that mimic a gut hormone released after eating and act on pathways involved in appetite, fullness, stomach emptying and blood-glucose regulation.
Options include semaglutide (Wegovy), tirzepatide (Mounjaro) and orlistat. Access and suitability vary, and prescription medicines require clinical assessment.
Common effects include nausea, diarrhoea, vomiting and constipation. Serious but less common problems require prompt advice. The patient information leaflet is the authoritative source.
Before use, they generally require refrigeration at 2–8°C and must not be frozen. Once removed, follow the exact product leaflet; where confirmed for the supplied pen, keep it below 30°C for up to 30 days.
Contraindications can include certain thyroid-cancer histories, MEN 2, pregnancy, breastfeeding, planned pregnancy or hypersensitivity. A prescriber must make the individual assessment.
