Resveratrol is a naturally occurring antioxidant compound found in red grapes, berries, and certain plants, often taken as a supplement for its purported health benefits. During pregnancy, many women question whether resveratrol is safe, particularly as it is marketed for cardiovascular and metabolic support. However, the safety of resveratrol supplements during pregnancy has not been adequately established through controlled human studies. Whilst dietary sources containing resveratrol are generally considered safe, concentrated supplements present different risks due to significantly higher doses. This article examines the current evidence on resveratrol safety in pregnancy, potential risks, and evidence-based alternatives recommended by UK healthcare guidance.

What Is Resveratrol and Why Do People Take It?

Resveratrol is a naturally occurring polyphenolic compound found in various plant sources, most notably in the skins of red grapes, berries (particularly blueberries and cranberries), peanuts, and Japanese knotweed (Polygonum cuspidatum). It belongs to a class of compounds called stilbenes and has gained considerable attention in recent years due to its purported antioxidant and anti-inflammatory properties.

Many people take resveratrol supplements based on potential health benefits, though it's important to note that most evidence comes from laboratory and animal studies rather than robust human clinical trials. The compound has been studied for its potential effects on cellular pathways associated with longevity and oxidative stress. While some preliminary research has investigated its role in cardiovascular health, blood sugar regulation, and inflammation, human evidence remains limited and inconsistent.

Common reasons people use resveratrol include:

• Potential cardiovascular health support

• Antioxidant supplementation

• Potential anti-ageing effects

• Metabolic health interest

• General wellness

Resveratrol supplements are available in various forms, including capsules, tablets, and liquid extracts, with doses typically ranging from 100 to 500 mg daily. However, there is no established safe or recommended dose for resveratrol, particularly in pregnancy. In the UK, these products are regulated as food supplements under food law, not as medicines. The Medicines and Healthcare products Regulatory Agency (MHRA) does not evaluate supplements for efficacy in the same way it does for licensed medications, meaning claims about health benefits may not be supported by high-quality clinical evidence.

It's worth noting that resveratrol supplements may interact with certain medications, particularly those affecting blood clotting, and quality can vary between products. While red wine contains resveratrol, it should be avoided during pregnancy due to its alcohol content.

Potential Risks of Resveratrol for Pregnant Women

The safety of resveratrol supplementation during pregnancy has not been adequately established through controlled human studies. Whilst resveratrol occurs naturally in foods and moderate dietary intake from food sources is generally considered safe, concentrated supplements present a different risk profile due to significantly higher doses than would be obtained through diet alone.

Animal studies have raised some concerns about resveratrol's effects during pregnancy. Research in rodents has suggested that high doses of resveratrol may interfere with foetal development, particularly affecting pancreatic function and potentially altering metabolic programming in offspring. Some studies have indicated possible effects on the developing reproductive system and hormonal balance, though the relevance of these findings to human pregnancy remains uncertain.

Key concerns include:

• Lack of human safety data: There are insufficient clinical trials examining resveratrol supplementation in pregnant women, making it impossible to definitively establish safety

• Potential hormonal effects: Resveratrol has demonstrated oestrogenic activity in laboratory studies, which could theoretically affect hormonal balance during pregnancy, though human relevance is unclear

• Potential placental transfer: Animal and laboratory studies suggest resveratrol can likely cross the placental barrier, meaning the developing foetus would potentially be exposed to supplemental doses

• Unknown effects on foetal development: The long-term consequences of prenatal resveratrol exposure in humans are not known

• Possible bleeding risk: Resveratrol has antiplatelet properties that could theoretically increase bleeding risk during pregnancy or delivery

The NHS and NICE do not recommend resveratrol supplementation during pregnancy, and the general principle is to avoid unnecessary supplements during pregnancy. The Royal College of Obstetricians and Gynaecologists (RCOG) advises that pregnant women should be cautious about taking any supplements beyond those specifically recommended for pregnancy, such as folic acid and vitamin D. Given the absence of robust safety data, healthcare professionals advise against taking resveratrol supplements during pregnancy as a precautionary measure.

Safe Alternatives to Resveratrol in Pregnancy

If you are considering resveratrol for its antioxidant or health-promoting properties during pregnancy, there are several evidence-based alternatives that are considered safe and are actively recommended for pregnant women in the UK.

Recommended pregnancy supplements include:

Folic acid (400 micrograms daily) is essential before conception and during the first 12 weeks of pregnancy to reduce the risk of neural tube defects such as spina bifida. Women at higher risk may require a higher dose (5 mg daily) as advised by their GP or midwife, in line with NICE guidance (NG201).

Vitamin D (10 micrograms daily) is recommended throughout pregnancy and whilst breastfeeding to support bone health in both mother and baby. This is particularly important in the UK due to limited sunlight exposure, especially during autumn and winter months.

For general antioxidant support, a balanced, varied diet rich in fruits and vegetables provides a safe source of polyphenols and other beneficial compounds without the risks associated with concentrated supplements. Foods such as berries, leafy greens, citrus fruits, and wholegrains offer antioxidants alongside essential vitamins and minerals.

Omega-3 fatty acids can support foetal brain and eye development. The NHS advises eating up to 2 portions of oily fish weekly (avoiding high-mercury species like shark, swordfish and marlin, and limiting tuna to no more than 2 steaks or 4 medium cans per week). If taking supplements, choose pregnancy-specific omega-3 or algae-based products and avoid cod liver oil or any supplements containing vitamin A (retinol), which can be harmful in excess during pregnancy.

If you have specific health concerns that prompted interest in resveratrol—such as cardiovascular health, inflammation, or metabolic issues—discuss these with your GP or midwife. They can recommend appropriate, evidence-based interventions tailored to pregnancy. NICE guidance provides clear recommendations for managing various conditions during pregnancy, and your healthcare team can ensure any treatment is both effective and safe for you and your baby.

When to Speak to Your GP or Midwife

It is important to have an open conversation with your GP, midwife, or obstetrician about any supplements you are taking or considering during pregnancy. This includes over-the-counter products, herbal remedies, and nutritional supplements, as these can sometimes interact with prescribed medications or affect pregnancy outcomes.

You should contact your healthcare provider if:

• You are currently taking resveratrol supplements and have recently discovered you are pregnant

• You are planning pregnancy and want advice about which supplements to take or discontinue

• You have specific health conditions (such as diabetes, hypertension, or autoimmune disorders) and are considering supplements for symptom management

• You experience any unusual symptoms after taking any supplement during pregnancy

• You are unsure whether a product you are using is safe during pregnancy

Your midwife or GP can provide personalised advice based on your medical history, current health status, and any pregnancy-related conditions. They can also refer you to specialist services if needed, such as obstetric medicine clinics for complex medical conditions during pregnancy.

The NHS provides comprehensive antenatal care, and your booking appointment (ideally by 10 weeks of pregnancy, in line with NICE guidance) is an ideal opportunity to discuss all medications and supplements. Be prepared to bring a list of everything you are taking, including brand names and doses, to facilitate accurate advice.

Remember that:

• Not all 'natural' products are safe during pregnancy

• Supplements marketed for general health may not have been tested in pregnant women

• Your healthcare team is there to support you in making informed decisions

• Evidence-based pregnancy supplements (folic acid and vitamin D) are available free on prescription for those eligible

If you have already taken resveratrol supplements during early pregnancy before knowing you were pregnant, try not to worry excessively, but do inform your midwife at your next appointment. They can provide reassurance and ensure appropriate monitoring if necessary. The precautionary principle in pregnancy means avoiding unnecessary supplements, but inadvertent exposure does not automatically indicate harm has occurred.

If you experience any suspected side effects from supplements, you can report these through the MHRA Yellow Card Scheme, which helps monitor the safety of all healthcare products including food supplements.

Frequently Asked Questions