Supplements for IVF: An Honest UK Guide to the Evidence and Safety

If you are going through IVF, it is natural to wonder whether supplements can help, and which ones you should take or stop. Here is the honest answer up front: "supplements for IVF" means the vitamins, minerals and other nutritional products people take around treatment, and no supplement has been shown to improve IVF success. The evidence is limited and mixed. Supplements are general nutritional support around the preconception window, not a treatment, and anything you take during a cycle should be checked with your fertility clinic first, because some products interact with the medicines and protocols used in IVF.

This guide sets out what the evidence does and does not show, which supplements are commonly paused before egg collection, what your male partner's timing looks like, and how to have a useful conversation with your clinic. It is based on the 2026 NICE fertility guideline (NG257), the position of the Human Fertilisation and Embryology Authority (HFEA) on treatment add-ons, routine NHS preconception advice, and the largest evidence reviews available. It is information, not medical advice: your clinic's guidance always comes first.

Can supplements improve IVF success?

No supplement has been proven to improve IVF success, and the highest-quality evidence is limited and mixed. The largest review of antioxidants for female subfertility, a 2020 Cochrane systematic review covering 63 trials and 7,760 women, rated the evidence for any live-birth benefit as very low certainty (and a 2026 editorial note records that several of its included trials have since been retracted or placed under expression of concern, which does not change its cautious conclusion and, if anything, reinforces it).⁴ The European Society of Human Reproduction and Embryology (ESHRE) reflected the same caution in its 2023 recommendations by not endorsing routine antioxidant add-ons such as CoQ10, melatonin or NAC for the general IVF population.⁸ The honest position is that supplements sit in a "may support general nutrition, not shown to change IVF outcomes, check with your clinic" zone.

It is worth being clear about why the evidence is weak rather than simply absent. Trials in this area are often small, use different doses, and measure different things. You will sometimes see a laboratory marker such as the number of mature eggs collected or an embryo grade look better in one trial, but a clean, repeatable translation into more babies has not been shown across the good-quality evidence.⁴ That is why reputable bodies stop short of recommending supplements as a way to change your result.

There is one area where the evidence is more settled, and it is not a supplement at all. The 2024 evidence review by Hart, the most comprehensive recent synthesis of nutrition and IVF, points to a balanced, Mediterranean-style dietary pattern as the foundation, with lifestyle factors such as not smoking, limiting alcohol and caffeine, and a healthy weight doing more of the work than any single capsule.³ If you take one thing from this section, let it be that the basics matter more than the bottles.

Which nutrients are studied around IVF, and what can they claim?

A handful of nutrients are studied in the context of fertility, but "studied" is not the same as "shown to improve IVF". In Great Britain, the only health claims a supplement is allowed to make are the general, authorised statements in the GB Nutrition and Health Claims Register, and those describe a nutrient's role in normal body functions, not any effect on IVF success. Some of the ingredients people ask about most, such as CoQ10 and myo-inositol, have no authorised health claim at all, and their evidence around IVF is limited and not established.

The table below separates the two things that often get blurred: what a nutrient is authorised to say about normal body function, and what the IVF-specific evidence actually shows.

Two honest caveats sit under that table. First, an authorised claim about "normal cell division" or "normal fertility and reproduction" describes a nutrient's everyday role in the body. It is not a statement that the supplement improves IVF, and it should not be read as one. Second, the ingredients with no authorised claim are the ones marketed most enthusiastically online, which is precisely where caution is needed: enthusiasm is not evidence.

Are fertility supplements safe to take during IVF?

Not all of them, and not at every stage, which is why disclosure to your clinic matters more than any single product. Many supplements that are sensible in everyday preconception care can become a problem once the stimulation protocol starts, either because they are hormonally active, because they thin the blood ahead of egg collection (a needle procedure), or because they interfere with the medicines used in IVF. The most important group to flag is hormonally active botanicals: chasteberry (Vitex) and Dong Quai act on hormones, and maca is biologically active in the body though its hormonal effects are not well established in people, so all are generally advised to be paused or checked during fertility treatment. High caffeine intake is also usually limited.

This has a direct, practical consequence. Some general fertility supplements are formulated for the preconception phase and contain exactly these botanicals. That does not make them unsafe in general use, but it does mean you should not assume a product that suited you before treatment is right to continue during a cycle. Read the label, and check every ingredient with your clinic before stimulation starts.

The table below lists the supplements clinics most often ask patients to pause or check. It is a general guide, and your clinic's specific protocol always takes precedence.

Two principles cover almost every situation. First, tell your clinic about everything you are taking, including "natural" and herbal products, because these are the ones least likely to come up unprompted and most likely to interact. Second, if in doubt, pause it during the active stimulation and egg-collection window and only resume if and when your clinic agrees.

When should you start, and when should you pause, supplements?

Timing is simpler than it looks. If you are going to take foundational preconception nutrition such as folic acid and vitamin D, start it in good time rather than at the last minute, ideally around three months before a cycle, so your everyday nutritional status is in a sensible place before treatment begins. Once stimulation starts, the direction of travel reverses: this is the point to pause or check anything hormonally active or blood-thinning, following your clinic's protocol, and to resume only if they agree.

Your male partner's timing is often the missed piece. Sperm take around 64 days to develop from early precursor cells to mature, motile sperm, with some estimates extending the range further, so anything he changes in the few weeks before egg collection makes little difference to the cells used in that cycle.⁷ If he is going to make dietary or supplement changes, the sensible window is at least two to three months ahead. As with the female side, the evidence that antioxidant supplements change outcomes is low to very low certainty rather than settled: the 2022 Cochrane review of antioxidants for male subfertility rated its findings as low-to-very-low certainty evidence.¹⁰ The lifestyle basics, not smoking, moderating alcohol, avoiding excess heat, and addressing weight, are the dependable part.

What should you check with your fertility clinic?

Everything you take, before you take it. The single most useful thing you can do is arrive at your nurse or consultant appointment with a written list, because most clinics will not open the supplement conversation themselves but every reputable one will engage with it if you bring it. A written list turns a vague "do you take anything" tick-box into a specific clinical exchange, and it protects you from interactions you would not spot yourself.

A simple format works well. In column one, list what you currently take, with the name, dose and how long you have taken it. In column two, list anything you are considering, and why. In column three, write your questions, for example: "Should I stop omega-3 before stimulation, and if so, when?", "Is there anything in your protocol I should pause?", and "Are any of my supplements a problem with my trigger medication?". This matters because people commonly turn to online forums for supplement advice during IVF, where discussion of CoQ10, vitamin D, omega-3, DHEA and myo-inositol circulates widely, often without any input from the person's own clinic.¹¹ A written list closes that gap.

Nutritional support around your IVF journey with FertilitySmart

In the lead-up to treatment, or in the gap between cycles, general preconception nutrition is the part with the clearest rationale: folic acid, vitamin D, and a sensible micronutrient base for both partners. This is preconception support, not a treatment, and it is not a way to improve your IVF result.

FertilitySmart Conceive for Women and Conceive for Men are formulated for this preconception window, not for use during an active IVF cycle. Conceive for Women contains chasteberry (Vitex), a hormonally active botanical, so it is not suitable to continue once treatment starts and must be checked with your clinic. If you are currently in treatment, follow your clinic's guidance first. To understand what a preconception formula contains and how the nutrients fit together, see our guide to fertility supplements for women and our male fertility hub, or the overview in The Complete Guide to Fertility Supplements.