An antiepileptic and mood stabiliser (valproate)
Sodium valproate
A broad-spectrum epilepsy medicine, also used in bipolar disorder — highly effective, but it must not be used in pregnancy or by people able to become pregnant unless strict safety conditions are met.
What is Sodium valproate?
Sodium valproate is an effective, broad-spectrum antiepileptic, also used in bipolar disorder. Its defining safety issue is that it can seriously harm an unborn baby, so it must not be used in pregnancy, or by anyone able to become pregnant, unless the strict conditions of a Pregnancy Prevention Programme are met — and, under newer UK rules, it is generally not started in people under 55 without two specialists' agreement. It also needs monitoring of the liver.
Education and reference only. This is a plain-language guide to Sodium valproate — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Sodium valproate (often known by the brand Epilim) is a broadly effective epilepsy medicine that works against many seizure types, and it is also used as a mood stabiliser in bipolar disorder and sometimes to prevent migraine. It is genuinely effective — but it carries a very serious risk in pregnancy, which now dominates how and when it can be used in the UK. As a result, it is used under strict safeguards, particularly for anyone who could become pregnant. It is taken as a long-term medicine in several forms.
How it works
Valproate is thought to work in several ways at once: it increases the level of a calming brain chemical called GABA, and it dampens overactive electrical firing in nerve cells (partly through effects on sodium channels). This broad action is why it works across many different seizure types and also helps to stabilise mood. The exact balance of these mechanisms is not fully understood, but the overall effect is to reduce the excess brain activity that causes seizures.
What it treats
Conditions Sodium valproate is used for
Practical use
How to take Sodium valproate
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it regularly as prescribed; do not stop suddenly, as this can trigger seizures or destabilise mood.
- If you are able to become pregnant, you must be on the Pregnancy Prevention Programme with highly effective contraception, and attend regular specialist reviews — never risk pregnancy while taking it.
- Report severe stomach pain, persistent vomiting, yellowing of the skin or eyes, or unusual tiredness — these can signal liver or pancreas problems, especially in the first months.
- Take it with food if it upsets your stomach; swallow modified-release tablets whole.
- Have new medicines checked, and tell any prescriber you take valproate.
Weighing it up
Advantages & disadvantages of Sodium valproate
Advantages
- Broadly effective across many seizure types, and useful in bipolar disorder.
- Long experience and several formulations, including once-daily modified-release options.
- Does not reduce the effectiveness of hormonal contraception (unlike some other antiepileptics).
Disadvantages
- Serious risk of harm to an unborn baby — tightly restricted for anyone able to become pregnant.
- Can affect the liver and, rarely, the pancreas; needs monitoring.
- Common nuisance effects include weight gain, hair thinning and tremor.
Practical use
Good to know
The most important thing to understand about valproate is its risk in pregnancy: taken during pregnancy it can cause serious birth defects and problems with a child's development. Because of this, in the UK it must not be used by anyone able to become pregnant unless the conditions of a Pregnancy Prevention Programme are met (including highly effective contraception and regular specialist review), and newer rules mean it is generally not started in people under 55 unless two specialists agree there is no suitable alternative. If this applies to you, do not stop it suddenly — but do speak to your specialist. Valproate can also affect the liver (especially early on) and, rarely, the pancreas, and can cause weight gain, hair thinning and tremor.
Who should not take it / use with caution
- People who are pregnant, and — unless the strict Pregnancy Prevention Programme conditions are met — anyone able to become pregnant.
- People with significant liver disease, or certain inherited metabolic (mitochondrial) disorders.
- People with a history of pancreas problems, used only with great caution.
Monitoring
- Liver function (before starting and during the first months)
- Full blood count (before surgery or if bruising/bleeding)
- Pregnancy-prevention review for anyone able to become pregnant; weight
Side effects
- Common: nausea, weight gain, hair thinning (which often grows back), tremor and drowsiness.
- Important: effects on the liver (especially in the first six months) — report yellowing, severe tiredness or vomiting; and, rarely, inflammation of the pancreas (severe stomach pain).
- Serious in pregnancy: birth defects and developmental problems in a baby exposed in the womb — the reason for the strict safeguards.
Key interactions
- It can raise the levels of some other medicines, including the antiepileptic lamotrigine (which is introduced more slowly as a result) and others.
- Some medicines and alcohol add to drowsiness or affect the liver; certain antibiotics can change valproate levels.
- Aspirin can increase valproate levels — have combinations checked.
Available as: Tablets (including modified-release), crushable and chewable tablets, granules, a liquid, and an injection used in hospital; Depakote is a related valproate form used in bipolar disorder.
Answers
Sodium valproate: frequently asked questions
Why is valproate so strictly controlled in pregnancy?
Taken during pregnancy, valproate can cause serious physical birth defects and problems with a child's learning and development. Because of this, it must not be used by anyone able to become pregnant unless the strict conditions of a Pregnancy Prevention Programme are met, and newer UK rules mean it is generally not started in people under 55 without two specialists agreeing no suitable alternative exists.
I take valproate and could become pregnant — what should I do?
Do not stop it suddenly, as that can trigger seizures. But do arrange to see your specialist promptly to review your treatment and contraception. If you are planning a pregnancy, this needs specialist input well in advance so a safer alternative can be considered.
Does valproate cause weight gain and hair loss?
Both can happen. Weight gain is relatively common, and some people notice hair thinning, which usually grows back (sometimes curlier). Tell your team if these bother you, as it may affect the choice of treatment.
Is Epilim the same as sodium valproate?
Yes — sodium valproate is the generic (active-ingredient) name and Epilim is a common brand. Depakote is a closely related form (valproate semisodium) used mainly in bipolar disorder. People are often kept on the same version to keep levels steady.
Authoritative sources
- BNF: Valproate (sodium valproate / valproic acid).
- electronic Medicines Compendium (SmPC): Epilim.
- MHRA: Valproate use by women and girls – Pregnancy Prevention Programme and 2024 regulatory changes.
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