Can you take Foundayo with statins?

Jump to: What the UK prescribing information says about each statin | Why the simvastatin dose is halved | Why taking simvastatin later in the day doesn’t replace halving the dose | The U.S. limit of simvastatin 20 mg a day doesn’t apply in the UK | Halving your simvastatin dose or changing statin | Why rosuvastatin needs caution above 20 mg | Why you can keep taking your usual atorvastatin dose | Simvastatin dose limits with other medicines | When to speak to your GP | Protein, strength exercise, and grapefruit | Take home message | Frequently asked questions | References

You can take Foundayo (orforglipron), a once-a-day GLP-1 tablet for weight management and type 2 diabetes, alongside a statin, a medicine used to lower cholesterol.¹

Foundayo can raise the amount of some statins in the blood, and higher statin levels increase the risk of side effects. Whether you need to change your statin dose depends on which statin you take.^1,2

If you take atorvastatin, you can keep taking your usual dose.^1,3

If you take simvastatin, the UK prescribing information says to halve your dose if you’re on Foundayo, regardless of the dose you take.¹ Your GP or Foundayo prescriber will need to make this change.

If you take rosuvastatin 20 mg or less, you can continue taking your usual dose. The UK prescribing information advises caution above 20 mg a day.¹

You may see advice online to limit simvastatin to 20 mg a day with Foundayo. This comes from the U.S. prescribing guidelines and doesn’t apply in the UK.

We recommend telling your prescriber which statin you take before starting Foundayo. Don’t change your statin dose yourself.

What the UK prescribing information says about each statin

Foundayo’s UK prescribing information, its Summary of Product Characteristics, is the official document prescribers work from. It names only 2 statins, simvastatin and rosuvastatin.¹

We found no study of pravastatin or fluvastatin with Foundayo, and the UK prescribing information doesn’t name either, so we can’t say whether Foundayo changes the amount of pravastatin or fluvastatin in the blood. That’s why we recommend telling your prescriber if you take either one.

Inegy contains two cholesterol medicines, simvastatin and ezetimibe, in one tablet.

If you take it, speak to your prescriber before starting Foundayo so they can review how to reduce your simvastatin dose.¹

Our GLP-1 medication compatibility checker lists other medicines and conditions to discuss with your prescriber.

Why the simvastatin dose is halved on Foundayo

In studies, Foundayo raised active simvastatin levels in patients’ blood,¹ and higher doses and blood levels of simvastatin increase the risk of muscle problems.²

This rise in statin blood levels likely explains the recommended dose reduction, although the UK prescribing information doesn’t explicitly explain this.

Muscle problems associated with statins include myopathy, where muscle damage causes pain, tenderness, or weakness, and rhabdomyolysis, a severe form in which muscle breaks down and can damage the kidneys.²

Simvastatin trials involved 41,413 people, and about 60% were in studies that typically followed participants for at least 4 years.

About 3 in every 10,000 people developed myopathy on 20 mg a day, rising to about 8 in 10,000 on 40 mg and about 61 in 10,000 on 80 mg.²

So the risk of muscle problems on statins is small at usual doses but increases at high doses. Those trials monitored people closely and didn’t allow some medicines that interact with simvastatin.²

We found no study measuring how much Foundayo changes myopathy risk on statins.

NICE says the risk of muscle pain, tenderness, or weakness with a statin is small, and the chance of developing rhabdomyolysis is extremely low.⁴

Simvastatin is a prodrug, which means we take it in an inactive form. Our body then converts it into simvastatin acid, the active form.³

In a 2026 study, Morse and colleagues gave 50 healthy volunteers a 20 mg dose of simvastatin alone and measured the amount of simvastatin and its active form in their blood.

They repeated the test in 38 volunteers after gradually increasing their Foundayo dose.

The study used a 36 mg Foundayo capsule, which produces blood levels similar to the 17.2 mg tablet available today.³

When people took Foundayo at doses equivalent to the 14.5 mg and 17.2 mg tablets, simvastatin acid rose to about 2 to 2.5 times its usual level, yet the inactive form didn’t rise. The 14.5 mg and 17.2 mg tablets are the 2 highest Foundayo doses.¹

We found no published measurements of simvastatin acid at lower Foundayo doses. The UK advice to halve your simvastatin dose applies whatever Foundayo dose you take, though, so tell your prescriber before your first tablet, even though you’ll start on 0.8 mg.¹

We also don’t know exactly how much simvastatin acid would rise with long-term use, as these studies involved healthy volunteers rather than people taking a statin every day.³

The researchers, who work for Lilly, the company that makes Foundayo, propose that our body converts more simvastatin into its active form, but this explanation isn’t proven.³

The large Foundayo trials, ATTAIN-1 and ATTAIN-2, didn’t record people’s statin doses, so they can’t tell us which simvastatin dose is safe alongside Foundayo.

The review by the U.S. Food and Drug Administration (FDA) reports that one person developed statin myopathy while taking simvastatin and Foundayo, and later recovered.

Does taking simvastatin and Foundayo at different times prevent the interaction?

Taking simvastatin 2 hours after Foundayo still raised simvastatin acid to 2.47 times its usual level, which Morse and colleagues described as similar to taking both at the same time.^1,3

Simvastatin is usually taken in the evening, so taking Foundayo in the morning would leave about 12 hours between them, but this hasn’t been tested.²

It takes 29 to 49 hours, or about 1 to 2 days, for the amount of Foundayo in our body to fall by half, and daily tablets keep it at a steady level after about a week. So Foundayo would still be present in the blood when you take simvastatin later that day.¹

We recommend following your prescriber’s dose change rather than relying on the time between tablets.

The U.S. limit of simvastatin 20 mg a day doesn’t apply in the UK

The U.S. prescribing guidelines say to take no more than 20 mg of simvastatin a day with Foundayo, and this is the limit you may see in AI summaries and on U.S. websites.

The UK prescribing information sets no maximum dose. It says to halve the simvastatin dose, whatever you take, and your prescriber can oversee this.¹

The U.S. and UK advice can lead to different simvastatin doses:

• Simvastatin 80 mg: the U.S. prescribing guidelines say to lower the dose to 20 mg. In the UK, simvastatin’s prescribing information says people on 80 mg who need an interacting medicine should have a lower dose or a different statin, so your prescriber will need to decide.²
• Simvastatin 40 mg: the U.S. and the UK prescribing information both say to lower the dose to 20 mg
• Simvastatin 20 mg: the U.S. prescribing guidelines recommend no change, while the UK prescribing information says to halve the dose to 10 mg
• Simvastatin 10 mg: the U.S. prescribing guidelines recommend no change, while the UK prescribing information says to halve the dose to 5 mg

Morse and colleagues measured the rise in simvastatin acid with simvastatin 20 mg, the dose the U.S. guidelines say doesn’t need changing.³

In the UK, your prescriber will refer to the UK prescribing information to determine your dose.

Halving your simvastatin dose or changing statin

Your GP or Foundayo prescriber must make any change. If you take simvastatin 20 mg, we’d recommend asking them whether halving your dose or changing statin would be more suitable. They’ll need to weigh up why you take a statin, your recent cholesterol results, and your other medicines.

If you’re already taking atorvastatin, you can continue your usual dose with Foundayo.³

The same applies to rosuvastatin at doses of 20 mg a day or less.¹

NICE groups statin doses by how much they lower cholesterol. It describes simvastatin 20 to 40 mg as ‘medium intensity’ and 10 mg as ‘low intensity’.⁴

So, halving 20 mg to 10 mg moves you down to low intensity, while halving 40 mg to 20 mg keeps you at medium intensity. NICE’s medium-intensity group also includes atorvastatin 10 mg and rosuvastatin 5 mg.⁴

These groups describe each statin taken on its own, though. Foundayo raises simvastatin acid, so we don’t know how much a halved dose lowers cholesterol alongside Foundayo, and we found no study measuring this.

That’s one reason to have a blood test for cholesterol and liver function 2 to 3 months after your dose changes, which NICE recommends after any statin change.⁴

The UK prescribing information doesn’t explicitly say when a statin dose change should start, so ask before you take your first Foundayo dose.

If you take 10 mg, simvastatin’s dose range starts at 5 mg, and some 10 mg tablets are scored so they can be split evenly, but brands may differ, so ask your pharmacist.²

Your GP usually prescribes your statin, while Foundayo is currently only available privately. Since you may have two prescribers, we recommend telling both before your first Foundayo dose and asking:

• Who will change my simvastatin dose, and when should the change start?
• Should I halve my dose, or is there a reason to change to another statin?
• If I take 10 mg, how would I take a lower dose?
• Who will arrange my blood test after the change?

Why does rosuvastatin need caution above 20 mg?

If you take rosuvastatin up to 20 mg, you can carry on as prescribed. The UK prescribing information advises caution above 20 mg and reports that the 17.2 mg Foundayo dose raised the total amount of rosuvastatin in the blood over time to about 1.7 times usual.¹

Morse and colleagues gave rosuvastatin 20 mg to 28 healthy volunteers on its own and to 22 alongside Foundayo.³

The FDA judged this increase too small to matter clinically, and the U.S. prescribing information has no equivalent caution.

The caution in the UK prescribing information applies to rosuvastatin 30 mg and 40 mg tablets, which weren’t tested, so the study doesn’t show how Foundayo affects rosuvastatin levels at these doses.

Foundayo’s prescribing information doesn’t say what caution involves, so your prescriber will need to decide whether your dose is still right for you.¹

Some people shouldn’t take rosuvastatin 30 mg or 40 mg. They include people who:⁵

• Have moderate kidney problems
• Have an underactive thyroid
• Have a personal or family history of inherited muscle disorders
• Have had muscle problems on a statin or fibrate (a medicine that lowers blood fats)
• Drink too much alcohol
• Are of Asian ancestry
• Take a fibrate

The prescribing information for rosuvastatin 30 mg and 40 mg says these doses must not be used when other medicines could increase rosuvastatin levels in the blood.⁵

Foundayo increases rosuvastatin levels in the blood. However, Foundayo’s prescribing information advises caution with rosuvastatin doses above 20 mg a day, rather than saying that 30 mg and 40 mg must be avoided.¹

So, the guidelines are slightly contradictory about what to do. If you take rosuvastatin 30 mg or 40 mg a day, ask your prescriber whether you need a lower rosuvastatin dose before starting Foundayo.

Why you can keep taking your usual atorvastatin dose

You can keep taking your usual atorvastatin dose on Foundayo, as neither the UK nor the U.S. prescribing information recommends a dose change, and the FDA’s review says no dose adjustment is required.¹

Unlike simvastatin, atorvastatin is taken in its active form, so Morse and colleagues say Foundayo’s effect on simvastatin acid doesn’t apply to atorvastatin.³

But the evidence is thin, because only 8 to 9 healthy volunteers took part in the study. They took atorvastatin 40 mg on its own, then again 4 hours after a Foundayo dose equivalent to the 14.5 mg tablet.³

In the study, taking atorvastatin with Foundayo increased the total amount of atorvastatin in the blood over time by 47%.

The researchers didn’t consider this increase large enough to be clinically important.³

NICE recommends 20 mg for preventing cardiovascular disease and 80 mg for people who already have it, and we found no study of atorvastatin 80 mg with Foundayo.⁴

Contact your GP or prescriber if you develop muscle pain, tenderness, or weakness you can’t explain.

Simvastatin dose limits with other medicines

If you take simvastatin with any of the medicines below, your prescriber will need to decide the dose before you start Foundayo. These medicines already raise the risk of muscle problems with simvastatin, so its prescribing information sets limits:²

• Amlodipine, verapamil, or diltiazem, which treat high blood pressure, and amiodarone, which treats severe heart rhythm problems: no more than 20 mg of simvastatin a day
• Fibrates other than gemfibrozil or fenofibrate: no more than 10 mg of simvastatin a day
• Gemfibrozil: must not be taken with simvastatin
• Ciclosporin, which helps prevent transplant rejection: must not be taken with simvastatin or rosuvastatin, and limits Foundayo to 9 mg^1,5
• Clarithromycin, an antibiotic, itraconazole, which treats fungal infections, and ketoconazole tablets: simvastatin must be paused during the course, and these medicines limit Foundayo to 9 mg^1,2

If you take amlodipine, you shouldn’t take more than 20 mg of simvastatin a day. Foundayo’s prescribing information also says to halve your simvastatin dose.

Before starting Foundayo, ask your prescriber whether you need a lower simvastatin dose or a different statin.

If you’re prescribed clarithromycin, itraconazole, or ketoconazole tablets, tell the prescriber you take Foundayo and simvastatin, and ask when to restart simvastatin.

Our guide to Foundayo with anticoagulants covers blood thinners in more detail.

When to speak to your GP

Contact your GP or prescriber the same day if you develop muscle pain, tenderness, or weakness you can’t explain. NICE recommends getting medical advice and having a blood test for creatine kinase, which checks for muscle damage.⁴

If creatine kinase is less than 5 times the upper limit of normal, NICE says your symptoms are unlikely to be due to the statin, and your GP should look for other causes.⁴

If it’s higher than that and you haven’t done strenuous exercise, simvastatin’s prescribing information says simvastatin should be stopped, and your GP will decide what happens next.²

These symptoms may be caused by your statin, and Foundayo can raise simvastatin and rosuvastatin levels.

Muscle problems aren’t listed as a side effect of Foundayo itself, but tell your GP or prescriber about Foundayo, your statin, and any other medicines you take.¹

Muscle pain on a statin often has another cause. NICE reports that about 16% of people on high-intensity statins had muscle pain, but only around 1 in 12 of those cases was likely to be due to the statin.⁴

Simvastatin’s prescribing information lists things that make rhabdomyolysis (severe muscle breakdown) more likely:²

• Being 65 or over
• Being female
• Kidney problems
• An underactive thyroid that isn’t controlled
• A personal or family history of inherited muscle disorders
• Past muscle problems on a statin or fibrate
• Drinking too much alcohol

The NHS lists muscle damage as a serious statin side effect, with cramps, severe pain, and weakness, and sometimes a high temperature and red or brown urine. If you have these symptoms, can’t reach your GP or prescriber, or think you might be having a serious side effect, call NHS 111.

Call NHS 111 now if you keep being sick and can’t keep fluids down. We also recommend contacting your prescriber the same day if vomiting stops you from taking your statin.

Vomiting and diarrhoea while taking Foundayo can lead to dehydration and kidney injury,¹ and kidney problems increase the risk of muscle problems when taking a statin.^2,5 The prescribing information doesn’t link these risks, so this is our own reasoning.

Our guide to Foundayo side effects covers these symptoms in more detail.

If worrying about taking several medicines is affecting your sleep or daily life, speak to your GP.

Protein, strength exercise, and grapefruit

Losing some muscle during weight loss is different from the muscle damage a statin can cause. To maintain muscle while losing weight on Foundayo, we recommend eating enough protein, losing weight slowly (around 1 lb a week), and doing regular strength exercise (1-2 times a week if possible).

Losing weight quickly can lead to more muscle loss, and eating enough protein is unlikely to maintain muscle mass without strength exercise.⁶

We also recommend staying on the lowest effective dose for as long as possible. Many of our members stay on lower doses of Wegovy, the Wegovy pill, Foundayo, or Mounjaro and achieve significant weight loss without losing excess muscle.

You don’t necessarily need to join a gym or do weights to start strength training; you could start with sit-to-stands from a chair or wall press-ups, then gradually do more as it feels manageable.

If you’ve had muscle aches on a statin, exercise may still help. In one study of 32 statin users, 16 of whom had muscle symptoms, a 12-week endurance and resistance programme improved strength without worsening their symptoms.⁷

The study was small and didn’t involve Foundayo, so still contact your GP or prescriber the same day if you get new muscle pain you can’t explain.

If you develop muscle aches, tell your GP about any recent hard exercise, because creatine kinase shouldn’t be measured after strenuous exercise.²

We recommend eating 3 balanced meals a day while you take Foundayo, with a protein portion about the size of your palm or open hand at each meal, plus protein-rich snacks if needed, such as tuna on rye crackers.

If you’re struggling to eat enough protein at your meals, try easier-to-digest protein sources, such as scrambled eggs, tofu, minced meat, or white fish.

If Foundayo is reducing your hunger so much that you’re skipping meals, speak to your prescriber about lowering your Foundayo dose.

Foundayo has no listed food interaction,¹ but grapefruit juice can increase the amount of some statins in the blood.

In one study, participants drank 240 ml of grapefruit juice in the morning and took simvastatin that evening. The total amount of simvastatin acid in their blood over time was 90% higher than without grapefruit juice.²

Simvastatin’s prescribing information therefore advises avoiding grapefruit juice.²

Atorvastatin’s prescribing information says not to drink large quantities, and over 1.2 litres a day for 5 days raised atorvastatin to 2.5 times usual. The prescribing information for Crestor (rosuvastatin) doesn’t mention grapefruit.⁵

Take home message

Take home message

You don’t need to change your atorvastatin dose when you start Foundayo.³

If you take simvastatin, your GP or Foundayo prescriber will need to halve your simvastatin dose. For example, 20 mg a day would be reduced to 10 mg a day.¹

The U.S. guidance allowing simvastatin 20 mg a day without a dose reduction doesn’t apply to UK prescriptions.

You don’t need a dose change on rosuvastatin 20 mg a day or less. If you take more than 20 mg a day, ask your prescriber to review your rosuvastatin dose before starting Foundayo.¹

Before starting Foundayo, tell your GP and Foundayo prescriber which statin you take and your daily dose. Don’t change your statin dose yourself.

Continue taking your statin as prescribed, even if you lose weight or your cholesterol improves.⁴

If your statin dose changes, ask who will arrange blood tests for cholesterol and liver function 2 to 3 months after the dose change.⁴

We also recommend eating enough protein and doing regular strength exercise to help maintain muscle while you lose weight.

At Second Nature, our registered dietitians and nutritionists help members plan balanced meals and eat enough protein while taking weight-loss medication.

Our balanced plate is half vegetables, a quarter protein, and a quarter complex carbohydrates, plus a serving of fat.

Our published JMIR study reported an average weight loss of 19.1% at 12 months among active subscribers on the semaglutide-supported programme.⁸

Among members with recorded 12-month weights, 77.7% lost at least 10% of their starting weight.⁸

Second Nature's Mounjaro and Wegovy programmes

Second Nature provides Mounjaro or Wegovy as part of our Mounjaro and Wegovy weight-loss programmes.

Why choose Second Nature over other medication providers, assuming you're eligible?

Because peace of mind matters.

We've had the privilege of working with the NHS for over eight years, helping people across the UK take meaningful steps toward a healthier, happier life.

Our programmes are designed to meet people where they are, whether that means support with weight loss through compassionate one-to-one health coaching, or access to the latest weight-loss medications (like Mounjaro and Wegovy) delivered alongside expert care from a multidisciplinary team of doctors, psychologists, dietitians, and personal trainers.

At the heart of everything we do is a simple belief: real, lasting change comes from building better habits, not relying on quick fixes. We're here to support that change every step of the way.

With over a decade of experience, thousands of lives changed, and a long-standing record of delivering programmes used by the NHS, we believe we're the UK's most trusted weight-loss programme.

We hope to offer you something invaluable: peace of mind, and the support you need to take that first step.

Frequently asked questions

Can I take Foundayo and my statin at the same time?

Yes, once your prescriber has reviewed your medications and made any dose changes.

You can take Foundayo once a day at any time, with or without food, and keep taking your statin at its usual time.¹

Unlike with the Wegovy pill, you don’t need to take Foundayo on an empty stomach or wait 30 minutes after taking it.

What should I do if I’m already taking Foundayo and simvastatin?

Contact your GP or Foundayo prescriber as soon as you can, because the UK prescribing information says you should halve your simvastatin dose.¹

Don’t change the dose yourself in the meantime. If you have muscle pain, tenderness, or weakness you can’t explain, contact them the same day, or call NHS 111 if you can’t reach them.

Does Foundayo lower cholesterol levels?

Yes. ATTAIN-1 was a 72-week trial of 3,127 adults with obesity or overweight who didn’t have type 2 diabetes.

In pooled results for the 5.5 mg, 9 mg, and 17.2 mg doses, non-HDL cholesterol (all cholesterol other than HDL) fell by an average of 7.57%, compared with 1.41% in people taking placebo.¹

The UK prescribing information says improvements in blood fats may come from losing body fat, including fat around the organs.¹

However, Foundayo isn’t a replacement for a statin. The main heart safety trial, ACHIEVE-4, compared Foundayo with insulin glargine in 2,749 adults with type 2 diabetes at increased cardiovascular risk.⁹

Over about 2 years, heart attacks, strokes, deaths from heart and circulation problems, and hospital admissions for unstable angina affected 4.2% of people on Foundayo and 5.0% on insulin glargine. This showed Foundayo wasn’t worse than insulin glargine, but the trial tested safety, not prevention, and didn’t compare Foundayo with a statin or placebo.⁹

Can I stop my statin once I’m on Foundayo?

Foundayo isn’t a replacement for your statin, so don’t stop taking it without speaking to your GP.

NICE also recommends a medication review every year for anyone on a statin, which is the time to ask whether your treatment still suits you.

If your statin is ever paused because of an interaction with another medicine, NICE says you should be reminded to restart it.⁴

Will I need extra blood tests?

You don’t need extra blood tests just because you’re taking Foundayo with a statin.

NICE recommends a blood test for cholesterol and liver function 2 to 3 months after any change to your statin.

It also says you shouldn’t measure creatine kinase if you have no muscle symptoms, so you’d usually only have that test if you develop muscle pain, tenderness, or weakness.⁴

Can I take Foundayo with blood pressure tablets?

Yes, but tell your prescriber. We recommend asking whether your tablets need reviewing because Foundayo can lower blood pressure, and low blood pressure was more common in people also taking blood pressure medication.¹

Low blood pressure can make you feel lightheaded or dizzy, so contact your prescriber if this happens.

What happens to my statin dose if I stop Foundayo?

Ask your prescriber what to do with your statin before you stop Foundayo, as Foundayo takes a few days to leave the body and there’s no guidance on when to return to your previous statin dose.¹

Don’t go back to your previous dose yourself. If your prescriber changes it, NICE recommends a blood test for cholesterol and liver function 2 to 3 months later.⁴

Do Mounjaro and Wegovy have the same statin rules?

No. Unlike Foundayo’s, the prescribing information for Mounjaro, the Wegovy injection, and the Wegovy pill doesn’t recommend a change in statin dose.

Our guides Mounjaro with statins and Wegovy with statins cover this in more detail.

References

1. Electronic Medicines Compendium. (2026). Foundayo 17.2 mg film-coated tablets: Summary of Product Characteristics.
2. Electronic Medicines Compendium. (2026). Simvastatin 10 mg film-coated tablets: Summary of Product Characteristics.
3. Morse, B.L., Coutant, D.E., Ma, X., et al. (2026). Clinical characterization of enzyme and transporter precipitants to evaluate drug-drug interactions for orforglipron, a small molecule glucagon-like peptide-1 receptor agonist. Clinical Pharmacology & Therapeutics, 120(4), 979-990.
4. National Institute for Health and Care Excellence. (2023). Cardiovascular disease: risk assessment and reduction, including lipid modification. NICE guideline NG238.
5. Electronic Medicines Compendium. (2026). Crestor 40 mg film-coated tablets: Summary of Product Characteristics.
6. Mozaffarian, D., Agarwal, M., Aggarwal, M., et al. (2025). Nutritional priorities to support GLP-1 therapy for obesity: a joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. American Journal of Clinical Nutrition, 122(1), 344-367.
7. Allard, N.A.E., Janssen, L., Aussieker, T., et al. (2021). Moderate Intensity Exercise Training Improves Skeletal Muscle Performance in Symptomatic and Asymptomatic Statin Users. Journal of the American College of Cardiology, 78(21), 2023-2037.
8. Richards, R., Whitman, M., Wren, G., et al. (2025). A Remotely Delivered GLP-1RA-Supported Specialist Weight Management Program in Adults Living With Obesity: Retrospective Service Evaluation. JMIR Formative Research, 9(1), e72577.
9. Klein, K.R., Wysham, C., Tuttle, K.R., et al. (2026). Cardiovascular safety of orforglipron versus insulin glargine in adults with type 2 diabetes at increased cardiovascular risk (ACHIEVE-4): a phase 3, event-driven, randomised, open-label, non-inferiority, active comparator trial. The Lancet, 408(10564), 1557-1570.