Weight-Loss Pills vs Injections: Why GP-Led Assessment Still Matters

A tablet is not automatically safer or simpler than an injection. When comparing weight-loss medicines, consider the dosing routine, possible side effects and your other medicines as well as whether you are comfortable with injections.

In June 2026, the MHRA approved the once-daily tablet for weight management. It contains semaglutide, the same active ingredient as the weekly Wegovy injection. Mounjaro contains tirzepatide, a different active ingredient, and is supplied as a weekly injection.

The Wegovy tablet is taken every day after fasting for at least eight hours, swallowed with a small amount of plain water, followed by a wait of at least 30 minutes before eating, drinking anything else or taking other oral medicines. Weekly injections do not require this daily fasting routine. A tablet may suit someone who wants to avoid needles; an injection may be more practical for someone who takes important medicines first thing in the morning, works changing shifts or finds daily dosing difficult.

Prescription weight-loss treatment is generally considered alongside changes to diet and physical activity. Eligibility depends on the medicine, but commonly includes a BMI of 30 or above, or a BMI of 27 to below 30 with at least one weight-related condition such as high blood pressure, raised cholesterol, pre-diabetes, type 2 diabetes, sleep apnoea or fatty liver disease.

Meeting these criteria does not guarantee a prescription. A clinician will also consider your medical history, current medicines, previous treatment, eating-disorder history and any other medical conditions that may affect whether a particular treatment is suitable.

Semaglutide should not be used during pregnancy or while breastfeeding. Women who could become pregnant are recommended to use contraception while taking it. If you are planning pregnancy, speak to your prescriber: semaglutide should be stopped at least two months before a planned pregnancy. If you become pregnant while taking it, stop treatment and contact your prescriber promptly.

Other weight-loss medicines can have different restrictions and stopping intervals, so follow the advice for the specific medicine prescribed.

Common GLP-1 side effects include nausea, reflux, constipation, diarrhoea and vomiting. Mild symptoms often improve as the body adjusts, but they should still be discussed at follow-up if they persist, worsen or are difficult to manage.

If vomiting or diarrhoea means you cannot keep fluids down, or you are passing much less urine than usual, seek urgent advice from your GP or NHS 111.

The MHRA has strengthened its warning about acute pancreatitis. If you develop severe, persistent abdominal pain, particularly pain spreading to your back, which may be accompanied by nausea or vomiting, stop taking your GLP-1 medicine and seek immediate medical attention. For severe or rapidly worsening symptoms, attend A&E. This could be pancreatitis.

Semaglutide has also been associated with a very rare eye condition called non-arteritic anterior ischaemic optic neuropathy, or NAION. Sudden loss of vision or rapidly worsening eyesight requires urgent ophthalmological assessment through eye casualty or A&E.

Tell your healthcare team that you use a GLP-1 medicine before surgery or a procedure involving general anaesthesia or deep sedation. Do not stop it before a procedure unless the clinical team advises you to do so.

The Wegovy tablet is taken once a day. It should be taken on an empty stomach after fasting for at least eight hours, swallowed whole with up to 120ml (approximately half a glass) of plain water, followed by a wait of at least 30 minutes before eating, drinking anything else or taking another oral medicine.

Do not split, crush or chew the tablet. Eating, drinking or taking another medicine too soon can reduce how much semaglutide the body absorbs.

The routine may be straightforward for someone who takes it on waking. It may be less practical if you need other medicines first thing in the morning. Discuss the timing with your prescriber rather than changing important medicines yourself.

The tablet dose is increased gradually. The approved schedule starts at 1.5mg once daily, then increases to 4mg and 9mg before the 25mg maintenance dose. Patients should remain at each dose for a minimum of one month before moving to the next dose. If needed, they can remain at the previous dose for longer. Do not increase the dose faster than instructed.

Some patients established on the 2.4mg weekly Wegovy injection may be moved to the 25mg daily tablet by their prescriber. In this specific transition, the tablet can be started one week after the last 2.4mg injection. This is not a general switching rule for lower Wegovy doses, Mounjaro or other weight-loss medicines.

Do not combine tablets and injections, overlap doses or calculate a switch yourself. Your prescriber needs to consider the medicine and dose you currently use, side effects, treatment interruptions, other medicines and whether the new routine is practical.

Prescription weight-loss medicines should only be supplied after a proper clinical assessment by a regulated provider.

MHRA has warned that prescription treatments are being advertised illegally on social media. In 2025, the regulator seized more than 5,000 illegally traded GLP-1 products.

Do not buy prescription medicines from social-media sellers, beauty salons, informal contacts or websites that supply them without an appropriate healthcare consultation. Illegally supplied or falsified products may contain the wrong ingredient or dose, harmful substances, or no active medicine.

Not everyone needs the same checks. Depending on your medical history, symptoms and the treatment being considered, a clinician may record weight, BMI and blood pressure and consider tests for cholesterol, HbA1c, liver function, kidney function or thyroid function. These results can identify weight-related risks, help decide whether treatment is appropriate and provide a useful baseline.

Follow-up should cover weight change, appetite, side effects, hydration, mood, new illnesses and changes to other medicines. The prescriber may continue, adjust, pause or stop treatment based on how you respond.

Do not wait for a routine follow-up if you develop the urgent symptoms described above. At DocTap, repeat prescriptions are reviewed by a GP, but NHS 111 or A&E may be the appropriate route when urgent assessment is needed.

Your NHS GP can discuss weight-management support and whether an NHS treatment pathway may be appropriate. DocTap also offers a GP-led medical weight loss service for private assessment. A GP can review your health and medicines and arrange blood tests where they are clinically useful.

An appointment does not guarantee that medication will be prescribed. If treatment is unsuitable, the consultation can still provide advice about safer or more appropriate next steps.