What medicines should you not take with Wegovy?

Wegovy (semaglutide) is a weekly injection used for weight loss. It works by mimicking a hormone called GLP-1, which reduces appetite, slows stomach emptying, and lowers blood sugar.

Wegovy doesn't tend to affect how oral medications are absorbed. The manufacturer says any effect on stomach emptying isn't usually enough to matter. The interactions worth knowing about are with other medications that lower blood sugar (like insulin and sulfonylureas), plus a handful that need precise dosing and regular monitoring that a remote service like Voy can't offer.

The table below shows whether each medication is safe to take with Wegovy, and whether Voy can prescribe you Wegovy alongside these medications.

Who shouldn't take Wegovy? (Wegovy contraindications)

Wegovy isn't suitable for everyone. Voy can't prescribe Wegovy if you:

• Are under 18 years old
• Are trying to conceive, pregnant, or breastfeeding
• Have an allergy or hypersensitivity to any ingredient in Wegovy
• Have a personal or family history of thyroid cancer
• Have multiple endocrine neoplasia type 2 (MEN-2)
• Have a history of pancreatitis (inflammation of the pancreas)
• Have severe digestive conditions such as Crohn's disease, ulcerative colitis, or gastroparesis (delayed stomach emptying)
• Have a history of gallstones (if you still have your gallbladder)
• Have diabetes-related eye problems (such as diabetic retinopathy)
• Have type 1 diabetes
• Have severe liver disease
• Have chronic kidney disease
• Have severe heart failure
• Have cancer requiring active treatment or monitoring every 6 months or more
• Have a current or past diagnosis of an eating disorder (except binge eating disorder)
• Have a history of solid organ transplant
• Have a history of epilepsy or porphyria

The eligibility assessment covers each of these, and a clinician reviews every answer before treatment is approved. Share your full medical history honestly so they can make the right call for you.

Medications we can't prescribe Wegovy with

Certain medications work within a tight dosing window and need regular blood tests to stay safe. As a remote service, Voy isn't set up for that level of monitoring, so if you take any of the medications below, it's safer to look at weight loss treatment through your GP.

The medications we can't prescribe Wegovy alongside include:

Blood thinners: warfarin, acenocoumarol

Heart rhythm and heart medications: flecainide, propafenone, quinidine, procainamide, disopyramide, digoxin

Immunosuppressants: tacrolimus, ciclosporin, everolimus, sirolimus, azathioprine

Mood stabilisers: lithium

Epilepsy medications: phenytoin, carbamazepine (if prescribed for epilepsy), lamotrigine (if prescribed for epilepsy), oxcarbazepine, valproic acid, sodium valproate, primidone, phenobarbital, divalproex, ethosuximide, zonisamide

Antipsychotics: clozapine

Diabetes medications: insulin, sulfonylureas (such as gliclazide, glimepiride, glipizide, tolbutamide, chlorpropamide), other GLP-1 medications used for diabetes

Other weight loss medications: orlistat, Mounjaro, retatrutide, Rybelsus

Other: methotrexate (if prescribed for cancer or IBD), theophylline, isoprenaline

If you take any of these, your prescriber will check during your eligibility assessment.

Note: Carbamazepine and lamotrigine are only off the table if they're for epilepsy, and methotrexate only if it's for cancer or IBD. If you take any of these for something else, like rheumatoid arthritis or a skin condition, you may still be eligible. Your prescriber will check during your assessment.

Medications you can take with Wegovy

Metformin

Metformin and Wegovy work in different ways and are a common pairing, particularly for women managing PCOS or people with type 2 diabetes.

Both can lower blood sugar, so it's worth checking in with your GP after a few months to see if your dose needs adjusting.

Birth control and contraception

You can take oral contraceptives alongside Wegovy. Studies have shown that Wegovy doesn't reduce the effectiveness of combined pills (like Microgynon, Rigevidon, and Yasmin) or progestogen-only mini pills (like Cerazette, Cerelle, and desogestrel). There's no need to use a barrier method as an extra precaution.

Contraception is recommended for anyone of childbearing age while on Wegovy, because it shouldn't be used during pregnancy. If you're planning to try for a baby, Wegovy needs to be stopped at least 2 months beforehand because it stays in your system for a long time. Any reliable form of contraception is fine in the meantime, including:

• The combined pill or mini pill
• The Mirena coil or copper coil
• The implant
• The injection
• Barrier methods like condoms

If you're switching from Mounjaro to Wegovy, it's worth knowing the contraceptive advice differs between the two. Mounjaro can reduce how well the pill is absorbed, so a barrier method is needed for 4 weeks after starting and after each dose increase. Wegovy doesn't have this issue.

Blood pressure medication

Most blood pressure medications work fine alongside Wegovy. This includes:

• ACE inhibitors: ramipril, lisinopril
• Angiotensin receptor blockers: losartan, candesartan
• Beta blockers: bisoprolol, propranolol
• Calcium channel blockers: amlodipine, felodipine

Worth knowing: losing weight on Wegovy often brings blood pressure down too. That's a positive overall, but it can mean your current dose becomes stronger than your body needs after a few months. Mention to your GP that you've started Wegovy so they can keep an eye on your readings and adjust your dose if it drops too low.

Levothyroxine

Levothyroxine and Wegovy can be taken together. Levothyroxine works within a narrow margin, so even small shifts in absorption can tip your thyroid levels too high or too low. That's why it needs a bit of extra care when starting Wegovy.

The medication itself is fine to keep taking. Just ask your GP to check your thyroid (a TSH blood test) around 8 weeks after starting Wegovy, and again 8 weeks after you settle on a stable dose. Some people find it helps to take levothyroxine on an empty stomach, on a different day from their Wegovy injection.

The same applies to liothyronine if that's what you take.

Antidepressants and anti-anxiety medications

Most antidepressants and anti-anxiety medications are safe to take with Wegovy. This includes:

• SSRIs like sertraline, citalopram, escitalopram, and fluoxetine
• SNRIs and atypicals like venlafaxine and mirtazapine
• Beta blockers used for anxiety like propranolol
• Benzodiazepines like lorazepam and diazepam

One worth flagging: mirtazapine is known to increase appetite, which is something Wegovy actively works against. For people who've gained weight on mirtazapine, that overlap can actually help.

A couple of things to be aware of:

• Antidepressants commonly cause nausea, diarrhoea, or tiredness, especially in the early weeks or after a dose change. Wegovy can cause the same. Taking both can make these side effects feel more pronounced.
• Wegovy can cause a small increase in resting heart rate (around 1 to 4 beats per minute). It's not usually a problem, but if you have anxiety, it might feel more noticeable at first.

If your mood or mental wellbeing changes after starting Wegovy, get in touch with the clinical team.

ADHD medications

There are no documented interactions between Wegovy and ADHD medications. The thing worth knowing is the overlap: most ADHD medications suppress appetite, and Wegovy does the same. Combined, the effect can be stronger than expected, especially in the first few weeks or after a dose increase.

Speak to your prescriber if:

• Your appetite drops to the point you're struggling to eat
• You're losing weight faster than expected
• You feel weak, lightheaded, or unwell from not eating enough

This applies to the main ADHD medications, including methylphenidate (Ritalin, Concerta, Equasym, Medikinet, Xaggitin), dexamfetamine (Amfexa), lisdexamfetamine (Elvanse), atomoxetine (Strattera), and guanfacine (Intuniv).

Knowing your daily calorie needs can help you stay on track. Use our TDEE calculator to estimate your maintenance calories and a sustainable target.

HRT (hormone replacement therapy)

HRT is fine to take with Wegovy. Non-oral forms (oestrogen gels like Oestrogel and Sandrena, patches like Evorel, sprays, and the Mirena coil) have no interaction with Wegovy.

Oral progesterone (like Utrogestan) is slightly different. The British Menopause Society (BMS) notes that weight loss injections may reduce how well oral HRT is absorbed. This matters because progesterone in HRT protects the womb lining. If absorption is reduced, that protection may not be enough, which can pose a health risk.

If you're on oral progesterone, the BMS suggests reviewing your HRT with your GP or provider. Report any unexpected bleeding straight away.

TRT (testosterone replacement therapy)

TRT and Wegovy can be taken together. This includes injectable testosterone (such as testosterone cypionate, enantate, or Nebido) and topical testosterone (such as Testogel, Testavan, or Tostran).

If your prescription also includes tadalafil or sildenafil for erectile function, those are fine with Wegovy too.

Hair loss treatments

Finasteride, dutasteride, and minoxidil can all be taken with Wegovy, whether oral or topical.

If you notice more shedding than usual after starting, it's worth knowing this can happen with rapid weight loss itself rather than the medication. It tends to settle once your weight stabilises.

Antibiotics

Most antibiotics are fine with Wegovy, including amoxicillin, flucloxacillin, and other penicillins. The thing to watch is overlapping side effects: both can cause nausea, vomiting, or diarrhoea, which can feel rougher in combination. Speak to your prescriber if side effects are bothering you before your next Wegovy dose.

Painkillers

• Paracetamol is the safest first choice for pain relief, with no interaction to worry about.
• Ibuprofen and other NSAIDs (like naproxen) are fine occasionally, but regular use can irritate the stomach. If you're already getting gut side effects from Wegovy, the combination can feel uncomfortable. For ongoing pain, ask your prescriber about paracetamol or another option.
• Co-codamol (paracetamol with codeine) is fine with Wegovy. Codeine can cause constipation, and so can Wegovy, so the two together may worsen it. Drinking plenty of water and staying active helps.

Antihistamines

Antihistamines have no known interaction with Wegovy:

• Non-drowsy: cetirizine (Piriteze, Zirtek), loratadine (Clarityn), fexofenadine (Telfast, Allevia)
• Sedating: chlorphenamine (Piriton), promethazine (Phenergan), diphenhydramine (Nytol)

The sedating ones can leave you drowsy, which can compound the tiredness some people feel on Wegovy.

Herbal supplements, vitamins, and other supplements

Tell your prescriber about any supplements you take at your consultation.

Standard vitamins, protein powder, collagen, creatine, and fibre supplements are all fine alongside Wegovy. Most herbal supplements are also fine, including ashwagandha, lion's mane, and echinacea.

A couple need a closer look:

• St John's Wort can speed up how the liver breaks down many medications. The direct effect on Wegovy hasn't been studied, but it's worth flagging at your consultation so your treatment can be monitored.
• Ginseng and fenugreek can lower blood sugar in some people. On their own this usually isn't an issue, but combined with diabetes medication like metformin it could push your blood sugar too low. Watch for shakiness, sweating, dizziness, or feeling unusually hungry, and speak to the clinical team if these happen.

Alcohol and Wegovy

You can drink on Wegovy, but moderation helps. Alcoholic drinks are calorie-dense and can stimulate appetite, both of which can slow your weight loss progress. Wegovy and alcohol can also cause nausea, stomach upset, and dehydration on their own, so the combined effect can feel worse than either alone.

Tolerance is the other thing to watch. As you lose weight, the same amount of alcohol tends to hit harder than it used to.

Recreational drugs and Wegovy

If you use recreational drugs, let the clinician know on your eligibility questionnaire. It matters because many recreational drugs act on the same systems Wegovy does (appetite, digestion, blood sugar, heart rate), and combining them can make the effects of either feel stronger than usual.

What to tell your prescriber before starting

The eligibility questionnaire walks you through your medications, medical history, and lifestyle. A clinician reviews everything before approving treatment. A few things to have ready:

• All prescription medications and doses
• Over-the-counter medications you take regularly
• Supplements, vitamins, and herbal products
• Your full medical history, including anything from the “Who shouldn't take Wegovy?” list above
• Whether you're trying to conceive, pregnant, or breastfeeding
• Any planned surgery or procedures involving sedation

Being thorough helps the clinician make the safest call for you.