Somavert (pegvisomant) is a brand-name drug prescribed in certain adults to treat acromegaly, a growth hormone disorder. It’s given as an injection under the skin once per day.

Somavert is approved by the Food and Drug Administration (FDA) to treat acromegaly in certain adults. A common cause of acromegaly is a pituitary tumor that makes too much growth hormone. Doctors may prescribe Somavert when other treatments, such as surgery or radiation, aren’t suitable or haven’t worked.

Somavert is a biologic and belongs to a drug class called growth hormone receptor antagonists. Somavert is not available in a biosimilar version.

Keep reading for specific information about the dosage of Somavert, including its strengths and how to use the medication. For a comprehensive look at Somavert, see this article.

Note: This article describes the typical dosage for Somavert provided by the drug’s manufacturer. When using Somavert, always follow the dosage prescribed by your doctor.

Read below for recommended dosages of Somavert and other details about the drug.

Somavert form

Somavert comes as a powder in a single-dose vial with sterile water in a prefilled syringe. You mix the powder with the water to form a solution for subcutaneous injection. You (or your caregiver) will inject the drug at home. For details about this, see “How Somavert is given” below.

Somavert is available in either a 1-day supply or a 30-day supply.

Somavert strengths

Somavert comes in the following strengths:

  • 10 milligrams (mg)
  • 15 mg
  • 20 mg
  • 25 mg
  • 30 mg

Typical dosage

Typically, your doctor will start by prescribing a high dose called a loading dose. A higher dose at the beginning of treatment helps the medication start working right away. Then they’ll adjust your dose over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.

The following information describes the dosage that’s commonly prescribed or recommended. However, be sure to use the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Dosage for acromegaly

If your doctor prescribes Somavert for acromegaly, your first dose will likely be 40 mg. The day after your first dose, your doctor will lower your dose to 10 mg. You’ll inject 10 mg once per day.

Every 4–6 weeks during treatment with Somavert, you’ll have a blood test to check your level of insulin-like growth factor-1 (IGF-1). (IGF-1 is a hormone.) Your doctor may adjust your dose up or down by 5 mg based on your IGF-1 level.

The maximum dosage of Somavert is 30 mg per day, except for the loading dose.

For more information about your specific dosage, talk with your doctor.

Long-term treatment

Somavert is meant to be used as a long-term treatment. If you and your doctor determine that Somavert is safe and effective for you, you’ll likely receive treatment long term.

Before you start using Somavert, your doctor will discuss your treatment plan with you.

The Somavert dosage your doctor prescribes will depend on several factors. These include:

  • your IGF-1 level
  • how your body responds to Somavert
  • the severity of your acromegaly
  • other medications you take

Other medical conditions you have can also affect your Somavert dosage.

Dosage adjustments

Your doctor may need to adjust your dosage if you take opioid medications, such as codeine or oxycodone (Oxaydo, Oxycontin, others). To find out what drugs may interact with Somavert, see the “Interactions” section of this article.

Be sure to tell your doctor about all medications you take and any other health conditions you may have.

Somavert comes as a powder in single-dose vials. You’ll mix the powder with the water in the package to make a solution. Then you’ll give the prepared solution as a subcutaneous injection.

Your doctor will give you your first dose of Somavert. Then, they’ll show you (or your caregiver) how to do it. Be sure to inject the drug according to your prescribed instructions.

You can self-inject Somavert under the skin in your abdomen, upper thigh, and buttocks. If a caregiver gives you your dose, they may use your upper arm. Do not inject the drug within 2 inches of your belly button. Also, be sure to choose a different site with each injection. Take care to avoid areas where you have a skin rash, broken skin, or bruising.

Here are some other important points to keep in mind with Somavert:

  • You should store Somavert in the refrigerator. About 10 minutes before your injection, take Somavert out of the refrigerator. Bringing the medication to room temperature can make the injection more comfortable. You can talk with your doctor about short-term storage options.
  • After you make the solution, you should inject Somavert only if the solution is clear. Call your doctor or pharmacist if it appears cloudy, hazy, or discolored or if you see foam or particles. It’s likely that you cannot use the dose.
  • Always give your injection within 6 hours after preparing the solution. After 6 hours, the drug will no longer work and you must discard it.

If you have questions about how to prepare or inject Somavert, talk with your doctor or pharmacist. You can also watch a video and download step-by-step instructions on the manufacturer’s website.


Some pharmacies offer labels with large print, braille, or a code you scan with a smartphone to convert text to speech. If your local pharmacy doesn’t have these options, your doctor or pharmacist might be able to recommend a pharmacy that does.

If you miss a dose of Somavert, skip the missed dose. Then take your next dose at your usual time. Do not take two doses at the same time to make up for the missed one. If you’re not sure whether you should take a missed dose or skip it, talk with your doctor or pharmacist.

To help make sure that you don’t miss a dose, try using a medication reminder. This can include setting an alarm or putting a note where you’ll see it, such as on your bathroom mirror or bedside table. You could also download a reminder app on your phone.

It’s important that you do not use more Somavert than your doctor prescribes. For some medications, using more than the recommended amount may lead to harmful effects or overdose. Symptoms of an overdose may include fatigue.

If you use more than the recommended amount of Somavert

Call your doctor right away if you believe you’ve used too much Somavert. Another option is to call America’s Poison Centers at 800-222-1222 or use its online tool. If you have severe symptoms, immediately call 911 or your local emergency number, or go to the nearest emergency room.

Below are some frequently asked questions about Somavert.

How long does it take for Somavert to start working?

Somavert starts to work a few days after your first dose. Because of how the drug works, you likely won’t feel the drug working in your body. Your doctor will monitor you during treatment to check whether the drug is working to treat your condition. With continued treatment, Somavert should help manage your acromegaly symptoms.

Talk with your doctor about what to expect with Somavert and pituitary tumor treatments. (A pituitary tumor is a common cause of acromegaly.)

What is the recommended maximum dosage of Somavert?

The recommended maximum dosage of Somavert is 30 mg per day. However, you’ll receive a one-time loading dose of 40 mg when you start Somavert. Then, your doctor will lower your dose to 10 mg. They may adjust your dose during treatment, depending on certain test results. For details about this, see the “Somavert dosage” section above.

If you have questions or concerns about your Somavert dosage, talk with your doctor or pharmacist. Do not increase your dosage unless your doctor recommends doing so.

The dosage in this article is the typical dosage provided by the drug’s manufacturer. If your doctor recommends Somavert for you, they’ll prescribe the dosage that’s right for you. Always follow the dosage that your doctor prescribes.

As with any drug, never change your dosage of Somavert without your doctor’s recommendation. If you have questions about the dosage of Somavert that’s best for you, talk with your doctor.

Besides learning about dosage, you may want other information about Somavert. These additional articles might be helpful:

Disclaimer: Medical News Today 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.