Repatha (evolocumab) is a prescription drug that’s used to treat high cholesterol and other heart-related conditions. Repatha can cause side effects that range from mild to serious. Examples include back pain and diabetes.

Specifically, Repatha is used to:

The active ingredient in Repatha is evolocumab. (An active ingredient is what makes a drug work.) Evolocumab is a biologic drug, which means it’s made from living cells.

Repatha comes as a liquid solution that you inject under your skin. This can be done with a single-dose prefilled syringe or a single-dose prefilled auto-injector called SureClick.

Keep reading to learn about the common, mild, and serious side effects that Repatha injections can cause. For a general overview of the drug, including details about its uses, see this article.

Below are a few of the more common side effects reported by people who took Repatha in studies. These side effects can vary depending on what condition the drug is being used to treat.

More common side effects in people using Repatha to lower cholesterol levels include:

More common side effects in people using Repatha to reduce the risk of heart attack, stroke, and certain heart surgeries include:

* To learn more about this side effect, see the “Side effects explained” section.

Most common side effects of Repatha are mild. Examples of mild side effects that have been reported with this drug include:

* To learn more about this side effect, see the “Side effects explained” section.

In most cases, these side effects should be temporary. And some may be easily managed. But if you have any symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And do not stop using Repatha unless your doctor recommends it.

Repatha may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

Note:After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Repatha, visit MedWatch.

Serious side effects are possible with Repatha. Serious side effects that have been reported in the drug’s studies include:

* To learn more about this side effect, see the “Side effects explained” section.

If you develop serious side effects with Repatha, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Below are answers to some frequently asked questions about Repatha’s side effects.

What are some of the dangers of using Repatha?

In most cases, Repatha’s side effects are mild and not dangerous. But it’s possible that Repatha injections may cause some serious side effects. For example, in the drug’s studies, some people reported an increased blood sugar level.

Symptoms of increased blood sugar include:

It’s important to let your doctor know if you have any of these symptoms with Repatha. To learn more about increased blood sugar levels with this drug, see the “Side effects explained” section below.

Does Repatha cause weight gain or loss?

It’s not likely. Neither weight gain nor weight loss were reported as side effects in studies of people using Repatha.

However, diabetes and increased blood sugar levels are rare side effects of Repatha. In some cases, weight gain or loss can be a symptom of these side effects.

Talk with your doctor if you have weight gain or loss that’s bothersome. They can try to determine the cause and help you find ways to manage it.

Can Repatha cause hair loss?

Probably not. Hair loss was not reported as a side effect in studies of people using Repatha.

But other medications that treat high cholesterol may cause hair loss. For example, hair loss is a rare side effect of cholesterol-lowering drugs called statins, including Lipitor (atorvastatin) and Zocor (simvastatin).

If your doctor prescribes a statin along with Repatha to lower your cholesterol, you may experience hair loss from the statin.

If you have hair loss while using Repatha, talk with your doctor. They can try to determine its cause and recommend ways to manage it.

Are there any side effects specific to Repatha SureClick injections?

No, the side effects of Repatha SureClick injections should be the same as those for when the drug is given with prefilled syringes.

One of the more common side effects of Repatha injections, including when using the SureClick autoinjector, is injection site reactions. The most common kinds of reactions reported in Repatha’s studies were discoloration, pain, and bruising at the injection site. These kinds of reactions are usually not serious.

To reduce your risk of an injection site reaction, try to inject Repatha in a different location each time you use it. You can inject Repatha into your belly, thigh, or upper arm. But avoid injecting the medication in areas where your skin is irritated, bruised, tender, or discolored.

Allowing Repatha to come to room temperature before injecting it can help reduce pain during injection.

It is important to note that needle caps on Repatha SureClick injections are made using latex. This could cause an allergic reaction if you have a latex allergy. Be sure to tell your doctor if you have a latex or rubber allergy so they can prescribe a safe form of Repatha for you.

Talk with your doctor or pharmacist to learn more about ways to reduce your risk of side effects with Repatha.

Does Repatha cause liver-related side effects?

Probably not. Liver-related side effects were not reported in studies of Repatha.

Keep in mind that other drugs your doctor may prescribe along with Repatha to lower your cholesterol may have liver-related side effects.

For example, statin drugs such as Lipitor (atorvastatin) and Crestor (rosuvastatin) may cause certain liver problems. If you take these drugs together with Repatha, there’s a risk you may have liver-related side effects from the statin. But these side effects are not caused by Repatha.

Talk with your doctor or pharmacist if you have concerns about what side effects to expect from Repatha.

Learn more about some of the side effects Repatha may cause.

Fatigue

Fatigue was a less common side effect reported in Repatha’s studies. In many cases, fatigue caused by Repatha is mild. But keep in mind that fatigue can also be a symptom of rare but more serious side effects Repatha can cause, including diabetes or increased blood sugar levels.

What might help

In most cases, fatigue caused by Repatha is mild and goes away on its own, but sometimes it can be a symptom of other serious conditions.

If you have prolonged fatigue or other symptoms such as increased thirst or increased urination along with it, let your doctor know. These can be signs that your blood sugar level may have increased. Your doctor will likely do tests to determine the cause of your fatigue. They’ll decide on the right treatment option for you based on the cause of your fatigue.

Joint and back pain

It’s possible that Repatha may cause joint pain and back pain. Both of these side effects were reported in Repatha’s studies, but back pain was more common.

Keep in mind, though, that joint and back pain can be a symptom of other Repatha side effects, such as the flu.

What might help

Over-the-counter (OTC) pain relievers, such as ibuprofen (Advil, Motrin) or acetaminophen (Tylenol), may help relieve your pain. You can also try resting and applying an ice or heat pack to the affected areas.

Before taking OTC medications, talk with your doctor or pharmacist. They’ll let you know if they’re safe for you based on other drugs you take or conditions you have.

Talk with your doctor if you have joint or back pain that’s not relieved by OTC medications. They can recommend other treatment options for you.

Increased blood sugar levels

Using Repatha can cause increased blood sugar levels or diabetes. This was a common side effect in studies of people using Repatha to help prevent stroke, heart attack, or the need for certain kinds of heart surgery. This side effect was not reported by people using Repatha to lower cholesterol.

Symptoms of high blood sugar can include:

What might help

It’s important to tell your doctor right away if you have symptoms of high blood sugar while using Repatha. If not treated, high blood sugar and diabetes can lead to serious complications over time, including kidney or eye disease and nerve damage.

If your doctor determines that you have high blood sugar, they’ll likely recommend treatment options to manage your blood sugar level. In some cases, these treatment options may include medications.

Allergic reaction

Like most drugs, Repatha can cause an allergic reaction in some people. Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, usually in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment option to manage your symptoms. Examples include:

  • an antihistamine you take by mouth, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Repatha, they’ll decide whether you should continue using it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Repatha, they may have you switch to a different treatment.

Keeping track of side effects

During your Repatha treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking new drugs or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how it affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Repatha affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before taking Repatha.

Warnings

Repatha can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Repatha is a good treatment option for you.

Talk with your doctor about your health history before you take Repatha. Be sure to tell them if any of the following factors apply to you:

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.