PCSK9 inhibitors: Uses, common brands, and safety info

Having high cholesterol (hyperlipidemia) is a risk factor for cardiovascular disease. Many people with hyperlipidemia take a type of medication called a statin, such as Lipitor (atorvastatin). For some, a statin is well-tolerated and effective in lowering cholesterol (lipid) levels. Others may take a high dose of a statin and still develop cardiovascular disease, or may not be able to tolerate a statin medication at all. 

In 2015, the U.S. Food and Drug Administration (FDA) approved two injectable prescription PCSK9 inhibitors that lower LDL cholesterol and prevent cardiovascular events: Repatha and Praluent. PCSK9 (proprotein convertase subtilisin kexin type 9) inhibitors work differently from statins. They can be used alone or in combination with a statin.

In 2026, the FDA approved Lipfendra (enlicitide), which is made by Merck. Lipfendra is the first oral PCSK9 inhibitor administered as a once-daily oral tablet for adults in addition to diet and exercise to lower LDL cholesterol. 

This article will discuss the uses, side effects, and safety information of PCSK9 inhibitors. The table below lists the currently available PCSK9 inhibitors.

What are PCSK9 inhibitors?

PCSK9 inhibitors are prescription medications that are injected under the skin (subcutaneously) or taken by mouth, depending on the medication, used to lower low-density lipoprotein cholesterol levels (LDL-C levels) and lower the risk of cardiovascular events. A PCSK9 inhibitor may be prescribed to patients who have genetic hyperlipidemia or who are at very high risk for cardiovascular disease (heart disease) and cannot tolerate statins, or when high-dose statins are not effective enough on their own.

How do PCSK9 inhibitors work?

PCSK9 inhibitors bind to proprotein convertase subtilisin/kexin type 9 (PCSK9). PCSK9 binds to low-density lipoprotein receptors (LDL receptors, or LDLR) on the surface of liver cells (hepatocytes). This PCSK9 inhibition increases the number of LDLRs that can clear LDL and thereby lowers LDL cholesterol (LDL-C) levels.

What are PCSK9 inhibitors used for?

PCSK9 inhibitors are used:

• To lower LDL cholesterol in people with high cholesterol, which may include heterozygous familial hypercholesterolemia or homozygous familial hypercholesterolemia, depending on the specific drug.

• To lower the risk of cardiovascular events such as heart attack and stroke in certain patients at high risk.

Who can take PCSK9 inhibitors?

Before taking a PCSK9 inhibitor, tell your doctor about all of your medical conditions and medical history. Tell your doctor about all of the medications you take, including prescription drugs, over-the-counter (OTC) medicines, and vitamins or supplements. 

Men

Men can take a PCSK9 inhibitor, provided they fit into one of the indications, and the healthcare provider determines a PCSK9 inhibitor will be safe and appropriate. 

Women

Women who are not pregnant or breastfeeding can take a PCSK9 inhibitor, provided they fit into one of the indications and are prescribed by their healthcare provider. 

People who are pregnant or breastfeeding

The effects of PCSK9 inhibitors on an unborn baby are not known. Tell your healthcare provider if you become pregnant while using a PCSK9 inhibitor. 

Breastfeeding while using a PCSK9 inhibitor is not recommended. 

Consult your healthcare professional for medical advice on PCSK9 inhibitors and pregnancy or breastfeeding. 

Children

• Praluent is commonly used in adults, but is also approved for use in pediatric patients 8 years and older with heterozygous familial hypercholesterolemia.   

• Repatha is commonly used in adults, but is also approved for use in pediatric patients 10 years and older with heterozygous familial hypercholesterolemia or homozygous familial hypercholesterolemia.

• Lipfendra is approved for use in adults and has not been studied in children. 

Older adults

Clinical trials for PCSK9 inhibitors did not find a difference in safety or efficacy based on age. Your healthcare provider may take your age, among other factors, into consideration when prescribing a PCSK9 inhibitor.  

Are PCSK9 inhibitors safe?

Recalls

No recalls were found on PCSK9 inhibitors. You can search the FDA database to find updates on recalls. 

Restrictions and warnings

Do not take a PCSK9 inhibitor if you are allergic to any component of the drug. 

Caution should be used with Repatha in people who are allergic to latex.

Before using a PCSK9 inhibitor, your healthcare provider will instruct you on administration. Follow your healthcare provider’s instructions and consult them with any questions or concerns. Also, be sure to follow storage requirements as described in the product labeling. 

Are PCSK9 inhibitors controlled substances?

No, PCSK9 inhibitors are not controlled substances.

Common PCSK9 inhibitors side effects

• Common side effects of Lipfendra include diarrhea and dizziness.

• Common side effects of Praluent are muscle pain, flu, and injection site reactions (redness, itching, swelling, tenderness, or pain at the injection site).

• Common side effects of Repatha include cold or flu-like symptoms, back pain, high blood sugar, and injection site reactions.

If you are taking a PCSK9 inhibitor and experience symptoms of an allergic reaction, such as hives, rash, skin sores, blisters, difficulty breathing, or swelling of the lips, tongue, or face, seek emergency medical treatment right away.

Other adverse events may occur. Consult your healthcare professional about what side effects to expect and how to address them. You can report side effects to your doctor. You can also report side effects to the FDA by calling 1-800-FDA-1088.

How much do PCSK9 inhibitors cost?

Because PCSK9 inhibitors are currently only available in brand-name form, they can be quite expensive. Insurance and Medicare prescription coverage vary by plan. Contact your insurance provider for up-to-date coverage information. You can also check the manufacturer's website of the drug you are prescribed for information on savings programs, as well as eligibility requirements. 

You can always use our free discount cards and coupons when filling and refilling your PCSK9 inhibitor prescription. Using a SingleCare card can save up to 80% on prescription prices. Ask your pharmacist to compare costs and see how you can save on your prescriptions.