Botox (onabotulinumtoxinA) and Aimovig (erenumab-aooe) are prescription drugs used to prevent migraine episodes. Botox has other uses as well. Both drugs come in injectable forms. Botox and Aimovig are not available as biosimilar drugs.

This article explains the main ways that Botox and Aimovig are alike and different. For more information about these drugs, including details about their uses, see the in-depth articles on Botox and Aimovig.

You may wonder whether Botox or Aimovig is available as a biosimilar.

Biosimilars are like generic drugs. But unlike generics, which are made for nonbiologic drugs, biosimilars are made for biologic drugs.

Whether each drug is available as a biosimilar is included in the list below. The list also includes the name of each drug’s active ingredient. (An active ingredient is what makes a drug work.)

Botox:

  • Available as a biosimilar: no
  • Active ingredient: onabotulinumtoxinA

Aimovig:

  • Available as a biosimilar: no
  • Active ingredient: erenumab-aooe

Biosimilars will have the same active ingredient core name as the brand-name drug. But they will have unique suffixes. This is the reason “-aooe” appears at the end of Aimovig’s active ingredient. This is to show that it’s distinct from biosimilars that may be created in the future.

Botox and Aimovig are both prescribed to help prevent migraine episodes. Botox has other uses as well. See the table below for details on the conditions each drug treats and prevents.

Condition treatedBotoxAimovig
migraine
overactive bladder
urinary incontinence due to a neurological condition
muscle spasticity
blepharospasm (twitching eyelid)
strabismus (crossed or misaligned eyes)
excessive underarm sweating
cervical dystonia (neck muscle spasms)

To learn more about Botox or Aimovig for treating your condition, talk with your doctor.

Botox or Aimovig and children

Botox is prescribed for children of certain ages to treat:

Unlike Botox, Aimovig is not prescribed for children.

For more information about the use of Botox in children, talk with your child’s doctor.

Here’s an overview of dosages and how you’ll receive Botox and Aimovig for preventing migraine episodes.

Dosage for preventing migraine episodes

Dosage detailsBotox for preventing migraine episodesAimovig for preventing migraine episodes
Formpowder that’s mixed with saline to form a liquid solution for injection into skin or muscleliquid solution in a prefilled syringe or pen for injection under the skin
Strengths• 100 units per vial
• 200 units per vial
• 70 milligrams per milliliter (mg/mL)
• 140 mg/mL
Dose155 units70–140 mg
Treatment (injection) frequencyonce every 3 monthsonce a month

Botox is also prescribed to treat muscle and gland overactivity in other areas, including the bladder, eyes, underarms, and limbs. See the “What are Botox and Aimovig used for?” section above. These uses aren’t addressed in the table above. To learn more about the dosages for all conditions Botox treats, see this Botox dosage article.

Botox and Aimovig may cause side effects ranging from mild to serious.

For more information about possible side effects, see the articles about Botox’s side effects and Aimovig’s side effects.

Mild side effects

Botox and Aimovig may cause mild side effects. The table below lists examples of mild side effects that have been reported with these drugs when administered for migraine episode prevention.

Side effectsBotoxAimovig
injection site reactions, including pain and discoloration
muscle cramps and spasms
muscle stiffness
muscle weakness
muscle pain
neck pain
headache
worsening of migraine
partial paralysis of the face
drooping eyelid
bronchitis
constipation
mild allergic reaction

This table may not include all mild side effects of these drugs. For more information on mild side effects of the two drugs, see Botox’s prescribing information and Aimovig’s prescribing information.

Serious side effects

In addition to the mild side effects described above, serious side effects may occur in people having Botox or Aimovig treatment. See the table below for a list of side effects that have been reported with these drugs when administered to help prevent migraine episodes.

Side effectsBotoxAimovig
spread of botulinum toxin effects*
new or worsening high blood pressure
severe constipation requiring medical treatment
severe allergic reaction

To learn about your specific risk of serious side effects from Botox or Aimovig, talk with your doctor or pharmacist.

* Botox has a boxed warning for this side effect. A boxed warning is the mostserious warning from the Food and Drug Administration (FDA). To learn more, see the “What are the warnings of Botox and Aimovig?” section below.

Get answers to some frequently asked questions about Botox and Aimovig.

Can Botox and Aimovig be prescribed together?

Yes, Botox and Aimovig can be prescribed together to help prevent migraine episodes. The 2021 American Headache Society supports combining treatments in certain situations.

If you continue to experience migraine episodes despite treatment with Botox or Aimovig, your doctor may recommend treatment with both. If you’d like to learn more about this, talk with your doctor.

Is Botox a better treatment option than Aimovig, or vice versa?

Studies of Botox and Aimovig have shown that both drugs are effective in preventing migraine episodes. But Botox and Aimovig do have some differences, and these differences may make one a better choice for you.

For example, Botox and Aimovig work in different ways and cause different side effects. Also, Botox is injected by your doctor in the clinic, but you’ll inject Aimovig at home.

Depending on your situation, one drug may be better for you than the other. If you’re considering treatment with Botox or Aimovig, talk with your doctor about which one might be best for you.

You may wonder whether Botox or Aimovig are effective for your condition.

Botox and Aimovig are both prescribed to prevent migraine episodes. The American Headache Society includes both drugs in its treatment recommendations for preventing migraine episodes. But they have slight differences in the types of migraine episodes they are prescribed to prevent.

Botox is effective at preventing migraine episodes in people who have more than 15 migraine episodes per month (chronic migraine), with each episode lasting more than 4 hours. On the other hand, Aimovig is effective at preventing migraine episodes in people with chronic migraine or episodic migraine.

It’s important to note that your results from Botox or Aimovig may differ from those reported in studies. Talk with your doctor about whether one of these drugs is right for you.

If you’d like to read more about how each drug performed in studies, see Botox’s prescribing information and Aimovig’s prescribing information.

Whether you have health insurance or not, cost may be a factor when you’re considering these drugs. Visit Optum Perks* to get price estimates for Aimovig when you use coupons from the site. It’s important to note that Optum Perks coupons cannot be used with any insurance copays or benefits.

And to learn more about the cost of Botox, see this cost article.

Botox and Aimovig are both brand-name drugs. These drugs do not come in lower cost biosimilar forms.

Keep in mind that what you’ll pay for either drug will depend on your treatment plan, health insurance, where you receive your care, and possibly the pharmacy you use. Talk with your doctor, pharmacist, or health insurance provider to find out how much you’ll pay for the drug you’re prescribed.

* Optum Perks is a sister site of Healthline.

Botox and Aimovig may not be right for you if you have certain medical conditions or other factors that affect your health. These may be referred to as warnings.

The two drugs share some of the same warnings, but they also have different ones. Some of these warnings are mentioned below. Before you start treatment with Botox or Aimovig, be sure to talk with your doctor if these warnings could apply to you.

Boxed warning: Risk of spread of toxin effects with Botox

Botox has a boxed warning for the risk of spread of toxin effects. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.

Botox contains the active ingredient* onabotulinumtoxinA, which is a harmful substance if it enters the bloodstream and moves away from the injection site. Symptoms may occur hours to weeks after the injection. Toxin effects may include:

The risk appears to be greatest for children treated for muscle spasticity and those who already have difficulty breathing or swallowing. However, it can happen in anyone receiving Botox injections.

If you experience any of these symptoms after receiving Botox, call your doctor right away. But if you feel your symptoms are life threatening, call 911 or your local emergency number. Or go to the nearest emergency room.

* An active ingredient is what makes a drug work.

Other warnings

In addition to boxed warnings, Botox and Aimovig have other warnings.

Before starting treatment with Botox or Aimovig, talk with your doctor if any of the following conditions or health factors apply to you.

  • Warnings for Botox:
    • if you have an infection where Botox will be injected
    • if you have a neurologic disorder that affects your muscles or movements
    • if you have a condition that affects your breathing
  • Warnings for Aimovig:
    • if you have high blood pressure
  • Warnings for both Botox and Aimovig:
    • if you’re pregnant or planning to become pregnant
    • if you’re breastfeeding or planning to breastfeed

To learn more about these drugs, see the in-depth articles on Botox and Aimovig.

Yes, it’s possible. Your doctor may suggest that you switch drugs if Botox or Aimovig isn’t helping to prevent migraine episodes.

People generally notice fewer migraine episodes soon after treatment with an injectable drug, such as Botox or Aimovig. You should know whether the drug is helping you after approximately 3 months.

You should not switch drugs or stop your current treatment unless your doctor recommends it. If you’re interested in exploring other treatment options, talk with your doctor.

Both Botox and Aimovig are effective at preventing migraine episodes. But Botox treatment is usually reserved for more frequent migraine episodes.

Talk with your doctor about the best drug for you. They can answer your questions so that you’re comfortable with your treatment plan. Some questions you may wish to ask your doctor about Aimovig and Botox for preventing migraine episodes include:

To learn more about Botox, see these articles:

And to learn more about Aimovig, see these articles:

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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.