Valproic Acid

Ethan Cullen
Author: Ethan Cullen Medical Reviewer: Tayler Hackett Last updated:

Valproic acid (VPA) is an anticonvulsant drug used to treat bipolar disorder, epilepsy, and migraines [1]. It comes in the form of tablets, syrups, and capsules. Side effects of taking valproic acid can include drowsiness, headaches, rashes, and constipation [2]. Side effects can range from mild to severe.

Valproic acid brand names

Valproic acid is sold under various brand names [1] [2]

  • Belvo
  • Depakote
  • Dyzantil
  • Convulex
  • Syonell

What is valproic acid prescribed for?

VPA is used to treat epilepsy and prevent epileptic seizures. The types of seizure VPA helps with include:

  • tonic-clonic seizures
  • absence seizures
  • partial seizures
  • generalized seizures
  • myoclonic seizures [3]

It is also used to help regulate mood in people with bipolar disorder and to prevent migraine headaches. Valproic acid is one of several types of valproate medications used to treat migraines and also includes valproate sodium and vaproate semisodium.[1]

How does valproic acid work?

VPA is an anticonvulsant or antiepileptic drug. It treats epilepsy and migraines by regulating and limiting electrical signals in your brain.

VPA also increases the production of a chemical called gamma-aminobutyric acid (GABA) in your brain. This blocks some nerve signals in your brain and has a calming effect which helps to regulate mood in people with bipolar disorder.[2]

How is valproic acid usually taken?

Valproic acid comes in tablets, capsules, and syrups. Your daily dose will depend on many things such as what you are taking it for, your age, and your weight [2]. Take your dosage at roughly the same time every day. You do not need to take it with food, however, this can prevent the medication from upsetting your stomach [1].

Take the exact dose prescribed by your doctor and ask them if you have any concerns about which form you should be taking or your dosage. Do not stop taking VPA, even if you no longer experience any symptoms. Your doctor may want to gradually reduce the dose you are taking.

If you miss a dose, you should take it as soon as you realize it. If it is too close to when you would normally take your next dose, it is okay to skip your missed dose and carry on taking it as normal. Never take more doses than your prescription to catch up on missed doses.

How long does Valproic Acid stay in your system?

This will depend on your dosage and how long you have been taking valproic acid. If you are concerned about how long it will stay in your system, speak to your doctor or pharmacist.

Valproic Acid side effects

Taking valproic acid can cause side effects. These range from mild inconveniences to severe side effects that require urgent medical attention.[1] [2]

Mild/common side effects:

  • Stomach pains and nausea
  • Diarrhea and constipation
  • Unusual tremors or shakes
  • Feeling overly tired
  • Headaches
  • Weight gain 
  • Loss of appetite
  • Irregular and delayed periods
  • Blurred vision and changes in eyesight
  • Rapid eye movements
  • Mood swings and agitation

Tell your doctor if these become a daily problem and do not go away

Severe side effects:

  • Rashes and tiny red or purple spots on the skin
  • Difficulty breathing or swallowing
  • Swelling of the face, eyes, lips, tongue, or throat
  • Yellowing of the eyes and dark urine; may be a sign of liver issues
  • Long-lasting nausea and vomiting
  • Unusual bleeding and bruising
  • Joint weakness

These are very rare; speak to your doctor as soon as possible or seek urgent medical attention if you experience any of these symptoms or those listed in the WARNING section of the label.

Valproic acid precautions

Your doctor will ask you some questions before prescribing valproic acid. This is to ensure you are being given the correct dose and if there are any better alternative medications.[1]

  • Tell your doctor if you have an allergic reaction to VPA or any of the ingredients in the form you will be taking. Ask your doctor or pharmacist for a full list of ingredients for the specific brand and form.
  • Make a note of all the medications you are currently taking and any medical conditions that you know of. It is important to be very thorough, as even vitamins, herbal supplements, and dietary supplements can cause adverse side effects and prevent medications from working properly.
  • Tell your doctor that you are taking VPA if you are going to have a medical procedure.
  • Tell your doctor if you have a history of confusion or momentary difficulties to understand what is going on.
  • Mention if you have ever been in a coma, are an HIV carrier, or have Cytomegalovirus.
  • VPA can make you drowsy. Make sure you are fully aware of your symptoms before you operate heavy machinery.
  • Alcohol can also add to the drowsiness and make your side effects worse. Your alcohol tolerance can change, too.

Additional contraindications

There are certain medical conditions that may lead to adverse side effects if VPA is taken. These include:

  • Liver disease
  • Hepatitis/hepatic failure
  • Hypersensitivity
  • Urea cycle disorder

Mitochondrial disorders caused by mutations in mitochondrial DNA polymerase-gamma (POLG; eg, Alpers-Huttenlocher Syndrome) and children under 2 years of age who are suspected of having a POLG-related disorder.

Valproic acid and pregnancy

For women with epilepsy, it is not recommended that you take valproic acid when pregnant for. It has been shown to increase birth defects in children born when mothers take it during pregnancy.[4]

If you plan on becoming pregnant soon or are currently pregnant, speak to your doctor about an alternative medication. You will only be prescribed VPA during pregnancy if your doctor does not think there is any alternative, or if the benefits outweigh the risks.

It is considered safe to breastfeed whilst taking valproic acid. However, if you notice any unusual changes in your baby’s breastfeeding habits, as well as yellowing of the skin, dark urine, and abnormal bruising then you need to tell your doctor immediately.[2]

Valproic acid drug interactions

You do not have to change your diet when taking valproic acid. It is recommended that you carry on eating as normal.[1] Be cautious when drinking alcohol as valproic acid may change your tolerance and it can make you drowsier than normal.

There are some medications that can change the way valproic acid works or make the side effects worse. Tell your doctor if you are taking any of the following and they may wish to monitor you more closely or change your dosages.[2]

  • Any other medication for epilepsy
  • Blood clot medication
  • Aspirin
  • Cimetidine, which is a medication used to treat stomach ulcers
  • HIV or AIDS medication
  • Any antibiotics
  • Medications for depression or other mood disorders such as diazepam
  • Cholesterol-lowering medication
  • Malaria medication such as chloroquine

Valproic acid storage and disposal

Valproic acid should be kept at room temperature in a dry environment (i.e., not in the bathroom where it can get humid).

Valproic acid and any other medication should be kept in a locked cupboard out of reach of children and pets. It is important you check that the packaging has a child-locked lid. If it does not, then take extra precautions to make sure children do not have exposure to valproic acid.

Do not dispose of the medication in general waste areas where children and pets may have access. If you do have leftover doses, speak to a pharmacist about the best way to dispose of them (although your doctor will typically prescribe the exact amount).[1]

Valproic acid overdose

Taking too much valproic acid can result in an overdose.

Overdose symptoms include:[5][2]

  • Passing out
  • Tremors
  • Intense nausea
  • Confusion or not responding to people
  • Difficulty breathing
  • Seizures
  • In some extreme cases, death

The amount of valproic acid that could result in an overdose will depend on your age and weight, among other factors. Never take more than you have been prescribed by a medical professional.

If you suspect you or someone you know has taken too much, you should seek advice from your pharmacist, doctor, or at the emergency room. If someone has taken an overdose and has fallen unconscious and will not wake up, or is having seizures, you should call 911 immediately.

  1. Medline Plus [Internet] National Library of Medicine (2019). ‘Valproic Acid’. Available from:
  2. NHS UK [Internet] (2021) ‘Valproic Acid’. Available from:
  3. Löscher W (2002). “Basic pharmacology of valproate: a review after 35 years of clinical use for the treatment of epilepsy”. CNS Drugs. 16 (10): 669–694.
  4. BBC News (20th April 2017) “New evidence in France of harm from epilepsy drug valproate”. Available from:
  5. Rissardo JP, Caprara AL, Durante Í. (2021). “Valproate-associated Movement Disorder: A Literature Review”. Prague Medical Report. 122 (3): 140–180.
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Ethan Cullen
Author Ethan Cullen Writer

Ethan Cullen is a medical writer with a Bachelor of Arts degree in Philosophy, Politics, and Economics from Oxford University.

Published: Nov 23rd 2022, Last edited: Nov 2nd 2023

Tayler Hackett
Medical Reviewer Tayler Hackett BSc, PGCert

Talyer Hackett is a medical writer and researcher with 10+ years of experience, holding B.A. in Psychology from the University of Liverpool.