Switching Providers Mid-Treatment: What You Need to Know

You can switch Mounjaro or Wegovy provider part-way through treatment, and many people do, usually because of cost, service quality or delivery problems. The key points are to plan ahead so you don't have a gap, have evidence of your current prescription ready, and choose a properly regulated service. Your new provider must carry out its own consultation and its prescriber decides your dose, which may not be the same as before. This guide walks through what to expect, how to keep treatment continuous and safe, and the red flags to watch for.

Why people switch provider

Your relationship with an online provider is a healthcare relationship, but it is also a service you pay for. People change provider for a range of reasons, including:

• Cost. The September 2025 rise in the UK list price of Mounjaro led many providers to raise their prices, and price differences between services became more noticeable. We do not quote prices, but you can see how services compare on our prices page.
• Service quality. Slow responses to messages, hard-to-reach clinicians or limited follow-up.
• Delivery problems. Late deliveries, problems with cold-chain packaging or limited delivery slots.
• Stock issues. A provider being out of stock of a particular strength.
• Clinical support. Wanting more structured check-ins, dietitian support or a clinician who reviews progress properly.
• Medicine availability. Wanting access to a medicine your current provider doesn't offer, such as a newly licensed tablet.

Whatever the reason, the safety principles are the same.

What the rules say about prescribing to people already on treatment

Online pharmacies in Great Britain are regulated by the General Pharmaceutical Council (GPhC). In February 2025 the GPhC strengthened its guidance for pharmacies providing services at a distance, including those prescribing weight-loss medicines. In summary, the guidance expects services to:

• Carry out an appropriate consultation rather than relying only on a questionnaire
• Verify a person's identity
• Independently verify information such as weight and height, rather than relying only on self-reported figures
• Make sure the prescriber has enough information to prescribe safely, including information about other treatment

This means a new provider cannot simply take your word that you are on a particular dose. They need to satisfy themselves, as a matter of professional responsibility, that continuing treatment is appropriate. This can feel like a hurdle, but it is there to protect you. Read more about these checks in our guide to ID and weight verification and our overview of who regulates online weight-loss services.

Step-by-step: switching without a gap

The following is a practical outline. Every provider's process is a little different, and it is the new prescriber who decides what to prescribe.

Step 1: Check how much medicine you have left

Work out when your current supply will run out. A Mounjaro KwikPen contains four weekly doses; Wegovy pens also contain a set number of weekly doses. Tablet treatments come in packs. Make a note of the date of your next due dose after your supply runs out. This is your deadline.

Step 2: Choose a regulated provider

Before you do anything else, check the new provider carefully:

• Is the pharmacy on the GPhC register? You can search the register online.
• Are prescribers registered with the GMC (doctors), NMC (nurses) or GPhC (pharmacist prescribers)?
• If the service includes doctors providing consultations in England, is it registered with the Care Quality Commission (CQC)?
• Does it require a proper consultation, ID check and weight verification?
• Does it provide clear information about follow-up, side-effect support and how to contact a clinician?

Our guides to choosing an online pharmacy for weight loss and getting weight-loss injections online safely cover this in more depth. You can compare regulated services side by side on our providers page and use our comparison tool.

Step 3: Gather your evidence

Most providers will ask for some or all of the following:

Gathering this before your consultation can speed things up considerably.

Step 4: Complete the new consultation early

Aim to start two to three weeks before you run out. This allows time for the consultation, any follow-up questions, identity and weight checks, dispensing and delivery. Temperature-sensitive injections need to be delivered in suitable packaging and stored in the fridge on arrival.

Step 5: Cancel your old subscription carefully

If your old provider runs a subscription, check the terms so you aren't sent a further supply you don't need. Don't cancel until your new provider has confirmed it will prescribe, so you aren't left without medicine.

Step 6: Tell your GP

Let your GP know which provider is now prescribing. Many providers ask your consent to do this directly.

Dose continuity: will you stay on the same dose?

This is the question people ask most often. The honest answer is: often yes, but not always, and it is the new prescriber's decision.

When continuing the same dose is likely

A new prescriber is more likely to continue your current dose if:

• You can show recent, continuous treatment at that dose
• There has been no significant gap since your last dose
• You are tolerating the dose well
• Your weight and health information support continuing treatment

When a prescriber may restart lower or pause

A prescriber may restart at a lower dose, ask for more information, or decline to prescribe if:

• There has been a gap in treatment. Both the Mounjaro and Wegovy product information advise caution after missed doses, and after a longer break a lower restart dose may be considered to reduce the risk of gastrointestinal side effects
• You cannot provide evidence of your current dose
• You have had significant side effects
• Your current weight or health has changed in a way that affects suitability
• There is evidence of a health condition that makes the medicine unsuitable

If you are told you need to restart at a lower dose, ask why. A good prescriber will explain their reasoning. It is usually about reducing the risk of nausea, vomiting and dehydration after a break.

For what to do after a missed dose, see our guide to Mounjaro missed doses and always follow your prescriber's advice.

Changing medicine at the same time

Some people use a change of provider to switch medicine as well, for example from Mounjaro to Wegovy, or from an injection to a tablet. This is a bigger change than switching provider alone, because there is no direct dose conversion between different medicines. It should be discussed fully with the new prescriber. Our guides to switching from Mounjaro to Wegovy and switching from an injection to a tablet explain the considerations.

Why avoiding a gap matters

It is tempting to think a week or two off makes little difference. The evidence suggests that weight-loss medicines work while you take them, and their effects on appetite begin to wear off once they are stopped.

Two trials illustrate this well:

These trials looked at stopping for many months, not short gaps between providers. But they show that appetite and weight tend to return without medicine, and short gaps can also mean restarting at a lower dose with side effects returning. Read more in our guide to weight regain after stopping GLP-1 medication.

Cost considerations when switching

Cost is often the trigger for a switch, so it is worth thinking about the full picture rather than the headline monthly figure. Factors that affect what you pay include:

• The medicine and dose (higher doses can cost more)
• Whether consultation, follow-up and delivery are included or charged separately
• Subscription terms, minimum commitments and cancellation rules
• Whether the provider offers ongoing clinical support or dietitian access
• Price changes over time, which have occurred across the market

Our guides to hidden costs of weight-loss treatment and how weight-loss injection pricing works explain these in detail, and the prices page compares services.

Red flags when choosing a new provider

Switching can expose you to unregulated sellers, particularly if you are searching for a lower price. Be cautious if a seller:

• Doesn't require a consultation or asks only a few tick-box questions
• Doesn't ask for ID or any verification of your weight
• Offers to supply any dose you choose without question
• Sells through social media, messaging apps or marketplace listings
• Offers "research" peptides, unbranded pens or vials of powder to mix yourself
• Isn't listed on the GPhC register, or uses a registration number that doesn't match its name and address
• Pressures you with countdown timers, limited-time offers or claims that "stock is running out"

The MHRA has repeatedly warned about fake and unlicensed weight-loss medicines sold online. Our guide to fake weight-loss jabs explains how to spot them. If you think you have received a fake product or had a reaction to one, report it through the MHRA Yellow Card scheme.

Keeping good records

A simple personal record makes future switches, GP appointments and reviews much easier. Consider keeping:

• A list of each medicine, dose and start date
• The date of every dose increase or decrease
• Your weight at regular intervals, and other measures such as waist size
• Side effects and how long they lasted
• Copies of dispensing labels or prescription confirmations
• The name of the provider and prescriber at each stage

Our guide to measuring progress beyond the scales offers ideas for tracking health changes beyond weight.

Switching from private to NHS treatment

If you become eligible for NHS treatment, the process is different from switching between private providers. NHS weight-loss medicines are prescribed according to NICE guidance (TA875 for semaglutide and TA1026 for tirzepatide) and local service arrangements, which may include specialist weight management services or, for tirzepatide, a phased rollout in primary care that began in June 2025. Being on private treatment doesn't automatically qualify you, and the NHS may assess your eligibility based on your weight and health before you started treatment. Ask your GP how local services work. Our guide to private versus NHS weight-loss treatment explains more.

What a good handover looks like

When you change provider, information about your treatment needs to travel with you. Unlike moving between NHS services, private providers don't automatically share records, so you are often the link between them. A good handover usually includes:

• A clear treatment history. Which medicine, which doses, and the dates of any changes.
• Your starting point. The weight and BMI at which you began treatment, which may be relevant to future eligibility decisions.
• Side-effect history. Including anything that led to a dose being held or reduced.
• Relevant health information. Any new diagnoses, blood test results or medicines started since you began treatment.
• Your GP details. So the new provider can, with your consent, keep your GP informed.

Some providers will let you download a summary of your consultations and prescriptions from your account. It is worth doing this before you close an account, as access may end afterwards.

Your right to your information

Under UK data protection law, you have the right to request a copy of the personal data an organisation holds about you, including healthcare records. If you need information from a previous provider and it isn't available in your account, you can ask them for it. Most providers have a privacy or data protection contact for this purpose.

Common mistakes to avoid

People switching provider sometimes run into avoidable problems. The most common include:

• Leaving it too late. Starting the process when you have one dose left leaves no margin for delays in checks or delivery.
• Stretching doses. Taking injections less often than prescribed to make a pen last longer can reduce the medicine's effect and may lead to a lower restart dose.
• Using leftover pens of a different strength. Mixing strengths or trying to take partial doses from a pen can lead to dosing errors. Only use your medicine as prescribed.
• Not mentioning gaps. Being open about missed doses helps your new prescriber choose a safe dose. Hiding a gap can lead to restarting at a dose that causes significant side effects.
• Choosing on price alone. A lower price may be appealing, but follow-up, clinical support and safe prescribing practices matter too.
• Forgetting to cancel a subscription. This can lead to unwanted deliveries and charges.

Questions to ask a new provider

Before committing, it is reasonable to ask a new provider:

• What evidence do you need from me to continue my treatment?
• Will you prescribe my current dose, and under what circumstances might you change it?
• How long does your consultation and approval process usually take?
• How are medicines delivered, and how is the cold chain maintained for injections?
• How do I contact a clinician if I have side effects or questions?
• How often will you review my progress?
• Will you share information with my GP if I consent?
• What are the terms if I want to pause, change dose or cancel?

Clear, straightforward answers are a good sign. Vague responses or pressure to commit quickly are not.

More guides on changing treatment are in our switching topic hub and the wider guides library.

When to speak to a professional

Speak to your current or new prescriber, your GP or a pharmacist if:

• You are about to run out of medicine and haven't yet arranged a new supply
• You have missed doses or had a gap in treatment
• You are unsure what dose you should be taking
• You have been offered a different medicine or dose and want to understand why
• You have side effects that are worsening or not settling
• You are pregnant, planning pregnancy or breastfeeding

Seek urgent medical help (NHS 111, or 999 in an emergency) if you have:

• Severe, persistent abdominal pain, which may spread to your back, with or without vomiting
• Repeated vomiting or diarrhoea with signs of dehydration, such as dizziness, very dark urine or passing very little urine
• Yellowing of the skin or eyes, or pain in the upper right abdomen with fever
• Signs of a serious allergic reaction, such as swelling of the face or throat, or difficulty breathing
• Any reaction to a product you suspect may be counterfeit