10 Best Supplements for PCOS Weight Loss
Looking for PCOS weight loss supplements? That's the honest beginning. No supplement has been shown to melt weight away in PCOS, now also called polyendocrine metabolic ovarian syndrome (PMOS) by the NHS. A few show early signs of small weight changes, blood sugar, or cholesterol. The majority of that evidence is of low to moderate quality.
This guide ranks ten commonly studied options by how directly the trials measured weight or related markers. It's not a shopping list but a map for a chat with your GP or chemist. Let’s break it down.
Quick answer
2023 international guideline: Lifestyle change comes first for PCOS
Of all supplements, inositol has the most research, but the evidence is limited and conflicting.
Vitamin D NHS advice is 10 micrograms a day in autumn and winter and no more than 100 micrograms a day.
If you take metformin, ask your doctor to check your vitamin B12 levels.
There is no evidence to support any claims that a supplement can “reverse” PCOS.
Do Supplements for PCOS Weight Loss Work?
Sometimes, in small ways, and not for all. A 2025 umbrella review of 46 randomised trials found that nutrition-based approaches are promising for PCOS. A Banner Health doctor sums up the state of play: most supplements have modest effects at best, and evidence is usually low- to moderate-quality.
Here’s why that matters. Insulin resistance is a common feature of PCOS, and being overweight can make it worse. Supplements that nudge insulin or blood sugar can help with weight indirectly, but studies often measure blood markers instead of kilos lost. Trials also differ in dose length and product, so results do not align neatly.
The 2023 guideline emphasises healthy lifestyle, mental health and shared decision-making. It also encourages clinicians to be on the lookout for weight stigma and disordered eating, which can happen in people with PCOS regardless of their weight.
The 10 Best Supplements for PCOS Weight Loss, Ranked by Evidence
The order reflects the degree to which studies measured weight or BMI directly, then other metabolic markers. The results are not promising.
1. Inositol (myo-inositol and D-chiro-inositol)
Inositol is a vitamin-like compound and is the most studied supplement in PCOS. In a 2023 network meta-analysis, inositol reduced body weight and BMI compared to placebo. But the guideline team’s own review describes the evidence as limited and inconclusive. Inositol can be considered, according to the guideline, based on personal preference, with limited harm noted. It does not recommend specific types, doses, or combinations.
Watch out: Metformin might do better than inositol for waist-hip ratio and hirsutism. Inositol is less likely to upset your stomach.
2. L-carnitine
The same network meta-analysis ranked carnitine as the top performer for reducing weight and BMI among the supplements it compared. The trials were small, and the review calls for larger studies. Few sources in the UK mention this, so ask your chemist about quality and interactions.
3. Probiotics
In the 2023 network meta-analysis, probiotics, which are live bacteria, also reduced weight and BMI compared with placebo and lowered triglycerides. Strains and dosages differed between trials. Choose products with good labels and stop if you get more bloating or stomach pain.
4. N-acetylcysteine (NAC)
A meta-analysis of 11 randomised trials of 869 women published in 2023 showed that NAC improved several metabolic measures. The authors refer to it as a possible alternative to metformin. A news summary mentions greater changes in BMI and body weight than with metformin. One older review found metformin did better for ovulation and pregnancy rates. Talk to your doctor first; early evidence so.
5. Omega-3 fatty acids
In the network meta-analysis, omega-3 reduced fasting blood glucose and improved the insulin resistance index. Omega-3s may help decrease insulin resistance, triglycerides, and possibly testosterone, says a Banner Health expert. The evidence for direct weight loss is thin.
6. Chromium
In the network meta-analysis, chromium lowered fasting insulin and was superior to omega-3 for insulin resistance. It also reduced triglycerides and total cholesterol. Those findings suggest it is more effective for insulin handling than weight.
7. Vitamin D
Banner Health says vitamin D deficiency is common in women with PCOS. Vitamin D did lower total cholesterol in the network meta-analysis, but the review didn’t highlight it for weight loss. Follow NHS advice – everyone should consider taking 10 micrograms (400 IU) a day in autumn and winter. Taking too much vitamin D over time can lead to hypercalcaemia, so do not take more than 100 micrograms (4,000IU) a day.
8. Selenium
The same review concluded that selenium, like chromium and omega-3, had a beneficial effect on glucose metabolism. Evidence for weight is not strong. Too much of any mineral can be harmful: read labels and ask your chemist.
9. Berberine
Berberine is a plant-based compound. The authors say the data are limited, but a review of nine randomised trials found no significant difference between berberine and metformin for insulin resistance or glycolipid metabolism. A smaller review gave the evidence a low quality rating. Ask your doctor before taking it with metformin or other medicines.
10. Vitamin B12 (if you take metformin)
This one isn’t a weight loss aid, but it’s important to a lot of people with PCOS. Vitamin B12 deficiency is a common side effect of metformin that can leave you very tired, according to the NHS. The summary of the 2023 guideline recommends screening people on metformin for low B12. Have a blood test done before you purchase a supplement.
Safety First: How to Choose and Take Supplements
Supplements are not risk-free just because they are sold without a prescription. These steps are:
First, speak to a professional. Tell your GP or chemist about all the medicines, supplements and herbal remedies you use. The NHS says some medicines and supplements can interact with metformin.
Stay within safe limits. Limit vitamin D to no more than 100 micrograms a day.
Get one product to start. Then you can see side effects and make a judgement on what works.
Don’t stock up on a lot of products. Welltory’s review warns that it’s a bad idea to mix and match supplements yourself and that the guideline cannot recommend any specific inositol combinations.
If you plan to become pregnant or are pregnant, tell your doctor. Don't assume a natural product is safe during pregnancy.
If you develop rashes, swelling, severe stomach upset, or unusual tiredness, stop and seek advice.
What Works Better for PCOS Weight Management
But lifestyle changes can help symptoms, says the NHS. It suggests:
eating a healthy, balanced diet, exercising regularly, trying to lose weight if you are overweight, and talking therapy if symptoms affect your mood
NHS Better Health has free tools to help you lose weight and be active. Doctors may also turn to medications.
Metformin is prescribed by the NHS for tiredness and weight problems, and weight loss medicines for people who are overweight. The 2023 guideline suggests considering metformin in adults with PCOS and a BMI of 25 or above, with lifestyle changes.
For some people, weight-focused plans can backfire. If you are distressed by thoughts about food or weight, or you restrict, binge, or purge, talk to your GP. The guideline states that doctors should consider disordered eating in PCOS regardless of weight.
Test Before You Supplement
Blood tests can determine if you even need a supplement. PCOS is one of the common reasons people visit the consultant gynaecologists at myGynaePlus, a women’s health clinic in West London. Its services page also lists blood tests including vitamin D, AMH, FSH, LH, oestradiol, thyroid and prolactin, as well as pelvic ultrasound. The clinic accepts self-referrals. Ask any provider if your symptoms need insulin or B12 checks too, and share results with your GP to keep your records complete.
How to Decide: A Simple Checklist
Write down your symptoms, goals and current medications.
Ask your GP what blood tests are right for you.
Pick one supplement with the most convincing evidence for your goal.
Keep a log of weight, periods, energy and side effects for 8-12 wks.
Speak with your doctor and quit what doesn’t help.
Next Steps
Book a GP appointment, take your list of supplements, and ask what tests might be helpful. MyGynaePlus-type clinics list these services if you want extra blood tests or a longer consultation, but your GP is still the route for prescriptions and NHS monitoring. Begin with food, exercise and sleep, and see supplements as an optional addition. This article is for general information only and does not replace the advice of your doctor or chemist.
FAQs About Supplements for PCOS Weight Loss
Which supplement is best for PCOS weight loss?
No single supplement is shown to be best. A network meta-analysis (2023) showed that carnitine, inositol, and probiotics reduced weight and BMI compared to placebo. Early evidence, so talk to your GP before buying anything.
Does inositol help you lose weight with PCOS?
It might help a bit. One meta-analysis reported lower weight and BMI compared to placebo. However, the review by the guideline team characterises overall evidence as limited and inconclusive. The guideline does note that personal preference can be a factor for considering inositol.
Can I take supplements with metformin?
Speak to your doctor or chemist first. The NHS has warned that some medicines and supplements may not be suitable to take with metformin. Metformin can also reduce vitamin B12, and it’s worth getting a blood test to check.
How much vitamin D should I take?
Most people need 10 micrograms (400 IU) a day, and everyone should consider this in autumn and winter, the NHS says. Do not take more than 100 micrograms (4,000 IU) a day, as too much can be harmful.
Do supplements replace diet and exercise for PCOS?
No. The 2023 guideline recommends lifestyle change as first-line care. Experts say a supplement on its own can’t reverse PCOS. Some people may benefit from added supplements. Your doctor can help you decide.
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