If you are considering starting a weight loss medication, or you have already begun treatment and want to know what to expect, one of the most common questions is: How much weight can you lose in a month? The answer is not a single number. It depends on the medication, your starting weight, your lifestyle, and how your body responds to treatment.
Weight management is not a one-size-fits-all journey. Whether you are just beginning to explore your options or you are ready to start treatment, understanding what is available, how each medication works, and how to access it safely is essential. With more weight loss medication options available in the UK than ever before, the most important first step is getting the right clinical guidance rather than relying on unverified sources or informal sellers.
Get in touch with our prescribing team, or complete our online consultation to find out which treatment is right for you.
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Quick Summary
The UK currently offers a range of MHRA-approved prescription weight loss treatments, including Mounjaro (tirzepatide) and Wegovy (semaglutide) as injectable GLP-1 options, alongside Saxenda (liraglutide) and Orlistat 120mg. All require a clinical assessment from a qualified prescriber before they can be dispensed. Safe, regulated access is available online through a GPhC-registered pharmacy — no GP referral or in-person appointment needed.
Why Choosing a Registered Online Clinic Matters
The rise of GLP-1 medications has brought with it a significant and worrying increase in counterfeit and unregulated products being sold through unofficial channels. These include social media platforms, messaging apps, and informal sellers who operate entirely outside the UK’s pharmaceutical regulatory framework. For patients, the risks are real and serious: unverified products may contain incorrect dosages, undeclared ingredients, or no active compound at all.
Our Superintendent Pharmacist and clinical lead speaks directly to this issue:
“At The Care Pharmacy, we have become increasingly aware of counterfeit or unregulated products being offered through social media platforms, messaging apps and informal sellers. I have personally been made aware of individuals attempting to source or sell unregulated medication. This should concern everyone because weight loss medication is not a lifestyle accessory or a social media trend, it is a prescription only medicine that requires proper clinical oversight by a pharmacist or doctor.”
— Mohammed Ismail Lakhi, MPharm, MRPharm, Superintendent Pharmacist & Owner, The Care Pharmacy
When you access treatment through a GPhC-registered online pharmacy, you benefit from:
- A clinical consultation conducted by a qualified independent prescriber
- Medication dispensed only from MHRA-licensed sources
- Formal prescription issued to meet UK regulatory requirements
- Ongoing prescriber support throughout your treatment
- Clear guidance on dosing, side effects, and when to seek further advice
- Full accountability and recourse if something goes wrong
None of these protections exist when purchasing through unregulated channels. The lower price or quicker delivery offered by informal sellers is never worth the clinical risk.

Prescription Weight Loss Medications Available in the UK
All prescription weight loss treatments in the UK require a clinical assessment before they can be dispensed. The main options currently available through our online clinic are:
- Mounjaro (tirzepatide): A once-weekly injectable dual GIP/GLP-1 receptor agonist. The most effective weight loss injection currently available in the UK, with clinical trial data showing average weight loss of up to 22.5% of body weight at the 15 mg dose over 72 weeks.
- Wegovy (semaglutide): A once-weekly GLP-1 injectable with a well-established clinical and real-world evidence base. Average weight loss of approximately 15% of body weight over 68 weeks at the 2.4 mg maintenance dose.
- Saxenda (liraglutide): A once-daily GLP-1 injectable. An older formulation with a strong safety record, typically producing average weight loss of approximately 6–8% of body weight. Available for patients who are not suitable for weekly injectables.
- Orlistat 120mg: An oral capsule taken with meals. Works by blocking approximately one third of dietary fat absorption. Less potent than injectable options but well tolerated when dietary fat intake is controlled.
Comparing the Options
Medication
Type
Frequency
Avg. Weight Loss
Starting Price
Mounjaro (tirzepatide)
Injectable
Once weekly
Up to 20–21%
From £149.99
Wegovy (semaglutide)
Injectable
Once weekly
14–17%
From £99.99
Saxenda (liraglutide)
Injectable
Once daily
6–8%
From £279.99
Orlistat 120mg
Oral capsule
Three times daily
5–7%
On consultation
What Realistic Weight Loss Looks Like Month by Month
One of the most frequently asked questions from patients starting treatment is how quickly they will see results. The honest answer is that results build progressively, and the first month is rarely the most significant in terms of the numbers on the scale.
For GLP-1 medications such as Mounjaro and Wegovy, the prescribing process involves a structured dose escalation period. This means you begin on a low starting dose, which is increased gradually over several weeks or months to minimise side effects and allow the body to adjust. The appetite-suppressing effects typically become noticeable within the first two to four weeks, with measurable weight loss following as caloric intake naturally reduces.
Broadly speaking, patients can expect the following progression:
- Month 1: Appetite suppression begins. Early weight loss of 1–3% of body weight is common as the starting dose takes effect.
- Months 2–3: Dose escalation continues. Most patients report noticeably reduced hunger and cravings. Weight loss typically accelerates to 3–6% of starting body weight cumulatively.
- Months 4–6: Many patients reach or approach the maintenance dose. Weight loss becomes more consistent and significant. Cumulative losses of 8–12% are frequently reported at this stage.
- Beyond 6 months: With consistent adherence, clinical trial data shows continued loss toward the published averages. Results plateau for some patients, which should prompt a review with your prescriber rather than self-adjustment of the dose.
Orlistat works differently, as it acts directly on fat absorption rather than through appetite suppression. Effects are present from the very first dose and are consistent throughout treatment, provided dietary fat intake remains controlled.
How to Access Treatment Safely Through Our Online Clinic
The process of accessing prescription weight loss treatment through our GPhC-registered pharmacy is straightforward and does not require you to visit a GP or attend an in-person appointment.
1
Complete a free online consultation. A clinical questionnaire covers your medical history, current medications, BMI, and weight loss goals.
2
Clinical review by a qualified prescriber. A registered independent prescriber reviews your answers and confirms suitability, typically within 24 hours.
3
Prescription issued and medication dispatched. Once approved, your treatment is dispensed from a licensed source and delivered discreetly to your door.
4
Ongoing clinical support throughout treatment. Our prescribing team remains available for dose reviews, side effect guidance, and clinical advice at every stage of your journey.
Maximising Results: What to Do Alongside Medication
No weight loss medication produces sustainable results in isolation. The clinical evidence is clear: patients who combine medication with consistent lifestyle habits achieve better and more lasting outcomes than those who rely on treatment alone. The medication creates the conditions for weight loss by reducing appetite and altering metabolic signals — but it is the patient’s daily choices that determine how much of that opportunity is realised.
Key habits that support treatment include:
- Adequate protein intake: Prioritising protein at each meal helps preserve lean muscle mass during weight loss and supports satiety between doses.
- Consistent meal structure: Eating regular, balanced meals reduces the likelihood of blood sugar fluctuations that can trigger hunger and cravings, particularly during the early stages of treatment.
- Regular movement: Low to moderate physical activity, such as walking, swimming, or resistance training, supports fat loss and helps maintain metabolic rate as weight decreases.
- Hydration: Adequate fluid intake is important for all patients on GLP-1 medications, particularly during the first few weeks when nausea is more common.
- Limiting ultra-processed foods and alcohol: Both can undermine the appetite-suppressing effects of GLP-1 medications and slow progress.
These habits are worth embedding during treatment, not just after it ends. Patients who use the treatment period to establish sustainable routines are significantly better placed to maintain their results once medication is eventually reduced or stopped.
Learn how much weight you could lose using our weight loss calculator:

Frequently Asked Questions
Below are answers to some of the more specific questions our clinical team regularly receives from patients.
Can I switch from Wegovy to Mounjaro partway through my treatment?
Yes, switching between GLP-1 medications is possible, but it must be managed by a qualified prescriber rather than attempted independently. The timing of the switch, the starting dose on the new medication, and any washout period required will depend on your current dose, how long you have been on treatment, and your clinical response to date. A consultation with your prescriber is the appropriate route before making any change.
Is Orlistat suitable as a long-term treatment, or is it only recommended for short-term use?
Orlistat has a well-established long-term safety profile and is clinically approved for extended use in patients who respond to it. Unlike GLP-1 medications, it does not suppress appetite but instead acts on fat absorption at each meal, so its effect is consistent as long as dietary fat intake is moderated. It remains a valid long-term option for patients who are not clinically suitable for injectable treatments or who prefer an oral medication. Regular prescriber reviews are still recommended to monitor progress and tolerability.
How do I know if a weight loss medication I have seen advertised online is genuine?
The only reliable way to ensure you are receiving genuine, licensed medication is to source it through a GPhC-registered pharmacy that issues a formal prescription following a clinical consultation. All registered online pharmacies in the UK are required to display the EU common logo on their website, which links to the GPhC register. If a seller does not require a consultation, does not issue a prescription, or cannot be verified on the GPhC register, the medication should be considered suspect regardless of how it is presented or priced.
What is the difference between Mounjaro’s mechanism of action and that of Wegovy, and does it matter clinically?
Wegovy (semaglutide) is a GLP-1 receptor agonist, meaning it activates a single hormone receptor pathway involved in appetite regulation and insulin secretion. Mounjaro (tirzepatide) is a dual GIP/GLP-1 receptor agonist — it activates both the GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) pathways simultaneously. The addition of GIP activation is widely considered to contribute to Mounjaro’s superior weight loss outcomes in clinical trials. Whether this dual mechanism is more appropriate for a specific patient depends on their individual health profile and clinical history, which is why a consultation with a prescriber is essential before starting either treatment.
My weight loss has stalled after several months on GLP-1 medication. Should I increase the dose myself?
No. Self-adjusting the dose of any prescription medication outside the guidance of a prescriber is not recommended and can increase the risk of side effects, particularly gastrointestinal symptoms. A weight loss plateau after several months of treatment is not uncommon and does not automatically mean the medication is ineffective. Contributing factors may include dietary drift, a reduction in physical activity, or a natural adaptation to the current dose. Your prescriber can review your progress and advise on whether a dose adjustment is clinically appropriate in your specific circumstances.
Are there patients for whom Saxenda would be preferred over Wegovy or Mounjaro, despite lower average weight loss?
Yes. Saxenda (liraglutide) may be clinically preferred in certain situations — for example, in patients who have previously tolerated liraglutide well in a different indication, those who require finer dose control through daily administration, or those for whom once-weekly injections are impractical due to schedule or adherence considerations. Clinical suitability, not efficacy statistics alone, determines which medication is appropriate for a given patient. A prescriber will weigh all relevant factors during your consultation.
What happens clinically if I miss a dose of a weekly GLP-1 medication?
If a dose of Mounjaro or Wegovy is missed, current clinical guidance advises taking it as soon as possible — if fewer than 5 days have passed since the missed dose was due, otherwise skip and resume the regular schedule. If fewer than four days remain until the next dose, the missed dose should be skipped entirely and the regular schedule resumed. Never take two doses within the same week to compensate. Consistently missing doses will reduce treatment efficacy and may disrupt the dose escalation schedule. If you are finding adherence to the weekly schedule difficult, speak with your prescriber about strategies to support consistency.
Choosing the Right Treatment for You
The best weight loss medication is not the same for every patient. It depends on your medical history, your BMI, any existing health conditions, your lifestyle, and your personal preference for injections versus oral treatment. What matters most is that any medication you take is prescribed following a proper clinical assessment — not chosen based on social media recommendations, price alone, or what worked for someone else.
The proliferation of counterfeit and unregulated products in the UK market makes this point more important than ever. The risks of sourcing prescription medication through informal channels extend far beyond efficacy — they include serious and potentially life-threatening adverse events. Proper clinical oversight is not an optional extra; it is an essential safeguard.
If you are unsure which option is right for you, our pharmacist-led prescribing team can help you weigh up the options based on your individual circumstances. The consultation is free, there is no obligation, and you will only ever be recommended treatment that is clinically appropriate for you. Contact us with any questions, or complete our online consultation to get started today.
This article was written by Pharmacy Mentor and clinically reviewed by Mohammed Ismail Lakhi, MPharm, MRPharm, Superintendent Pharmacist & Owner at The Care Pharmacy. Mohammed is registered with the General Pharmaceutical Council (GPhC registration number 2072815) and leads clinical governance across the pharmacy’s weight management services.
Last reviewed: June 2026
Disclaimer: This article is for general information only and is not a substitute for individual medical advice. Always consult a qualified prescriber before starting any prescription weight loss treatment.
Medically reviewed by
Mohammed Lakhi
Superintendent Pharmacist