Can I Take Antacids When Pregnant?
Heartburn and indigestion are among the most common complaints of pregnancy, and many women find themselves reaching for antacids for the first time. The good news is that certain antacids are considered suitable for use in pregnancy — but not all of them, and there are important things to check before you take any medication while pregnant.
Quick Answer
Many antacids are suitable for use during pregnancy, but you should always check with your pharmacist, GP, or midwife before taking any medication. Antacids containing aspirin should be avoided. Tell the pharmacist you are pregnant so they can advise you on the safest option.
Why Heartburn Is So Common in Pregnancy
Heartburn and acid reflux affect a large proportion of pregnant women, particularly from the second trimester onwards. Progesterone relaxes the valve at the top of the stomach (the lower oesophageal sphincter), which allows stomach acid to travel upward into the oesophagus. As your uterus grows and puts pressure on your stomach, the problem often worsens. Spicy foods, fatty meals, eating late at night, and lying down shortly after eating can all make it worse.
Which Antacids Are Suitable in Pregnancy?
Some commonly used antacids — such as Gaviscon, Rennie, and certain Maalox preparations — are frequently used during pregnancy. However, formulations vary between products and brands, so always read the label carefully and check with a pharmacist before purchasing.
Antacids to avoid in pregnancy include:
- Products containing aspirin (sodium bicarbonate-based antacids or Alka-Seltzer with aspirin) — aspirin is not recommended during pregnancy unless prescribed by a doctor
- Products containing sodium bicarbonate in large amounts — these can cause fluid retention
- High-dose antacids — taking more than the recommended dose of any antacid during pregnancy is not advised
Always tell the pharmacist you are pregnant before buying any over-the-counter antacid. They can confirm which product and dose is appropriate for your stage of pregnancy. The same applies at any pharmacy, including supermarkets.
NHS Guidance on Medication in Pregnancy
The NHS advises that you should always speak to a healthcare professional before taking any medication in pregnancy, including over-the-counter medicines and herbal remedies. Some medicines that are perfectly safe at other times can harm a developing baby, particularly in the first trimester when organs are forming.
Your GP or midwife may be able to prescribe a suitable antacid or, if symptoms are severe, a medicine to reduce stomach acid production. Do not hesitate to ask — heartburn in pregnancy can be genuinely miserable and there is no need to suffer in silence.
Self-Help Measures for Heartburn in Pregnancy
Before reaching for antacids, it is worth trying some simple lifestyle changes, which can provide real relief for many people:
- Eat smaller, more frequent meals rather than three large ones
- Avoid eating within two to three hours of going to bed
- Sit upright after eating — avoid lying down immediately after meals
- Prop up the head of your bed slightly with extra pillows if night-time heartburn is a problem
- Avoid foods that trigger symptoms, which commonly include fatty or spicy food, chocolate, caffeine, and citrus
- Wear loose clothing that does not put pressure on your abdomen
These measures will not work for everyone, and for some people antacids or prescribed medication are genuinely necessary alongside them.
What If I Took Antacids Before I Knew I Was Pregnant?
Try not to panic. Taking a small amount of most medications before you knew you were pregnant is unlikely to cause harm. Contact your GP or midwife for reassurance and mention it at your booking appointment so it can be noted.
Frequently Asked Questions
What if I already took antacids before knowing I was pregnant?
Don't panic. Taking a small amount of most medications before you knew you were pregnant is unlikely to cause harm. Contact your GP or midwife for reassurance and mention it at your booking appointment.
Can I buy antacids over the counter while pregnant?
Yes, but always tell the pharmacist you are pregnant before buying any antacid. They can advise whether the specific product is suitable for pregnancy and suggest alternatives if needed. Not all antacids are the same, and formulations vary.
When should I see a GP about heartburn in pregnancy?
See your GP if heartburn is severe, persistent, or not responding to antacids. They can prescribe medication that is safe in pregnancy and rule out other causes of abdominal discomfort. You should also contact your GP or midwife if you have difficulty swallowing, are vomiting blood, or have lost weight as a result of symptoms.
This article is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider.
Last reviewed: June 2026
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