If you have certain skin conditions, your doctor might suggest Ilumya as a treatment option for you. It’s a prescription drug used to treat moderate to severe plaque psoriasis in adults.

The active ingredient in Ilumya is tildrakizumab-asmn. (The active ingredient is what makes the drug work.) Ilumya is a biologic medication (which means it’s made from living cells).

Ilumya is given as a subcutaneous injection (an injection under your skin). This is done by a healthcare professional in a doctor’s office.

For more information about Ilumya, including details about its uses, see this in-depth article.

Ilumya is usually a long-term treatment. Like other drugs, Ilumya can cause mild to serious side effects, also known as adverse effects. Like other biologics, this drug has effects on the immune system. Keep reading to learn more.

Some people may experience mild to serious side effects during their Ilumya treatment. Examples of Ilumya’s commonly reported side effects include:

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

The most common side effects are also the more mild ones. Examples of mild side effects that have been reported with Ilumya include:

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

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

Ilumya may cause mild side effects other than the ones listed above. See the Ilumya 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 Ilumya, visit MedWatch.

You might experience serious side effects during Ilumya treatment, although these were rare in the drug’s studies. Serious side effects that have been reported with this drug include:

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

If you develop serious side effects during Ilumya treatment, 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.

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

Injection site reactions

Injection site reactions are skin reactions that happen in the place where your doctor injects Ilumya. They can be mild to serious and were a common side effect in Ilumya studies.

You’ll receive Ilumya as a subcutaneous injection (an injection under your skin). Unlike medications you take at home, your doctor will give you this injection. They’ll choose a site where your skin is healthy (meaning it doesn’t have bruises, psoriasis plaques, or scars). This may be your belly, upper arm, or thigh. An injection-site reaction is possible in any of these places.

There were several kinds of injection side effects. The reactions were mild to serious and included:

What might help

You’ll receive your Ilumya injection at a doctor’s office or other healthcare facility. Your doctor can talk with you about how to manage any injection site reactions you might have.

For a mild reaction, you can use a cool compress to help decrease the inflammation at the injection site. You can also take an over-the-counter pain reliever or antihistamine to help with pain or itching.

If the reaction is severe or doesn’t go away in a few days, talk with your doctor. An injection site reaction can lead to a serious skin infection if not treated. Learn more about subcutaneous injections in this article.

Upper respiratory infection

An upper respiratory infection was a common side effect in studies of Ilumya, but severe infections were rare. This kind of infection is in your nose, ears, throat, or lungs. An example of an upper respiratory infection is the common cold. Because Ilumya weakens your immune system, you’re more likely to get an infection while being treated with this drug. An upper respiratory infection could be caused by several different kinds of bacteria or viruses.

Symptoms of infection that you should watch out for include:

What might help

Infections will sometimes go away on their own with time, rest, and supportive care. It’s important to drink plenty of fluids and get lots of rest to help your body heal from infection.

There are also over-the-counter medications* you can get to help with your symptoms:

* Be sure to talk with your doctor or pharmacist before taking over-the-counter medications.

For some infections, your doctor may prescribe an antibiotic for you. Be sure to take it exactly as directed and finish all the medication even if you start feeling better.

Talk with your doctor if you have symptoms that feel severe or don’t go away. You should also tell them if you develop a cough that doesn’t go away or a cough with blood. Rarely, Ilumya can cause severe infection, including tuberculosis (TB). If the infection is serious, your doctor may suggest that you temporarily stop Ilumya treatment. This will allow your immune system to clear the infection faster.

If you have a lot of infections while using Ilumya, your doctor may consider a different treatment for your condition.


Studies of Ilumya reported diarrhea, but most people who took the drug didn’t report this side effect. Diarrhea is loose or watery bowel movements that may occur very often. You can have mild to severe diarrhea and may also have some of the following symptoms:

If you have diarrhea, keep track of your symptoms and how long they last. If it’s more than a few days, let your doctor know. It could be a sign of an infection. Other signs that diarrhea may be part of a serious condition are:

What might help

If you have diarrhea that’s severe or lasts a long time, it’s important to figure out the cause. For serious diarrhea, this might involve a fecal test or a colonoscopy. The test results will help your doctor decide on the best treatment for your condition.

There are also ways to treat mild diarrhea symptoms. You can drink lots of fluids with electrolytes. For example, juice or some non-caffeinated sports drinks have electrolytes. This helps your body stay hydrated if you’re losing too much fluid due to the diarrhea.

You can also eat plain foods that are easy to digest. For example, toast and applesauce are mild foods for most people. Stick to foods that you know are easy on your stomach. You can avoid foods and drinks that commonly make diarrhea worse, such as:

  • alcohol
  • spicy foods
  • dairy products
  • fatty foods

Be sure to wash your hands well after using the bathroom. This helps prevent the spread of infection.

If your doctor says it’s safe for you, you can take an over-the-counter medication such as Imodium. This medication can help your symptoms, but it’s not always the best choice if your diarrhea is caused by an infection.

Allergic reaction

Like most drugs, Ilumya 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 to manage your symptoms. This could include:

  • an over-the-counter oral antihistamine, such as Benadryl (diphenhydramine)
  • a topical product, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Ilumya, they’ll decide if 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 Ilumya, they may have you switch to a different treatment.

Keeping track of side effects

During your Ilumya 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 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 Ilumya affects you. They can then use this information to adjust your treatment plan if needed.

Get answers to some common questions about Ilumya’s side effects.

Can I use Ilumya if I have an infection?

You may be able to use Ilumya if you have an infection, it depends on whether it’s mild or serious. Infection was a common side effect in studies of Ilumya, especially upper respiratory infection.

Your doctor may have you wait until your infection clears up before having you start treatment. This is because Ilumya decreases your body’s ability to fight infections.

If you have a latent tuberculosis (TB) infection, your doctor may prescribe a TB treatment while you use Ilumya. Or they may choose a different medication for you. The manufacturer of Ilumya includes a specific warning about TB in the prescribing information.

If you’re already using Ilumya and you develop a new infection, your doctor might stop your treatment temporarily.

Are biologics safer than creams or lotions for psoriasis?

Ilumya is a biologic medication (which means it’s made from living cells). Biologics, including Ilumya, are not necessarily more or less safe than creams or lotions used to treat psoriasis. The side effects are just different for each drug.

For example, one kind of psoriasis treatment is steroid cream. These creams often have side effects of thinning skin and sun sensitivity. Another kind of psoriasis treatment is vitamin D cream. These creams have a rare side effect of disrupting your body’s normal use of calcium.

There are many different kinds of psoriasis treatments, and each kind has side effects to consider. Read more about psoriasis treatments and side effects in this article.

Other biologic drugs used to treat psoriasis include Humira, Orencia, and Cosentyx. Although most biologic drug studies report decreased immune function, other side effects are different depending on the drug. Talk with your doctor about whether a biologic drug such as Ilumya is a good choice for you.

Will I develop antibodies to Ilumya?

Yes, you might develop antibodies to Ilumya, though this was rare in studies of the drug.

Sometimes your immune system mistakes a biologic drug for a bacteria or virus it needs to kill. So your body may develop antibodies that stop Ilumya from being an effective treatment. Your doctor will do frequent blood tests to check for this. Even if your body makes some antibodies against Ilumya, the drug might still be effective. Talk with your doctor about how often you should get tested while using Ilumya.

There are several warnings to keep in mind when considering treatment with Ilumya. This drug may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before starting Ilumya. The list below includes factors to consider.

Frequent infections. Ilumya makes your body less able to fight infection. So if you already get frequent infections, Ilumya could make them worse. Your doctor can help you manage your infections before you start Ilumya.

Live vaccines. If you’re planning to get a live attenuated vaccine soon, talk with your doctor about waiting to start Ilumya. It’s a good idea to be up to date on your vaccinations before you begin treatment with this drug.

Tuberculosis. Ilumya may cause active disease in people who already have tuberculosis (TB). If you have TB, talk with your doctor about whether Ilumya is the right drug for you. If you’ve been in close contact with someone who has TB, be sure to get a TB test before you start Ilumya.

Allergic reaction. If you’ve had an allergic reaction to Ilumya or any of its ingredients, your doctor will likely not prescribe it for you. Ask them about other treatments that might be better options for you.

Alcohol use and Ilumya

Alcohol and Ilumya don’t interact directly, but a possible side effect of each is diarrhea. Because of this, consuming alcohol during treatment with Ilumya could increase your risk of this side effect.

Alcohol is a psoriasis trigger for some people. If you drink alcohol and it worsens your psoriasis, Ilumya may not work as well.

If you drink alcohol, talk with your doctor about how to limit your intake during your Ilumya treatment.

Pregnancy and breastfeeding while using Ilumya

There are not enough studies yet to know whether Ilumya is safe for use during pregnancy and breastfeeding. Talk with your doctor about the risks and benefits of Ilumya in these situations.

Ilumya may cause side effects that your doctor can help treat. Here are a few possible questions for you to ask them:

  • Am I at increased risk of any of Ilumya’s side effects?
  • How can I tell when an infection is bad enough to call the doctor’s office?
  • Will a different biologic drug cause fewer side effects than Ilumya?
  • How do the side effects of Ilumya compare with my other treatment options for psoriasis?

For advice on managing your condition and news on treatments for it, sign up for Healthline’s psoriasis newsletter.


Can I get vaccines during the course of my Ilumya treatment?



You can get most vaccines while using Ilumya. There are two possible reasons that your doctor may advise you to be careful.

One reason is that your body may not respond as strongly to vaccines while using Ilumya. This is because Ilumya weakens your immune system, and your body might not make antibodies the same way it normally would. For this reason, your doctor may suggest you get any necessary vaccines before starting Ilumya.

Another reason is that live vaccines might be more likely to make you sick while you’re using Ilumya. A live attenuated vaccine is a weakened version of a germ that causes illness. These vaccines won’t cause the illness in people with normal immune system function. But if you’re using Ilumya, these live vaccines have a chance of causing illness. Ilumya’s manufacturer recommends avoiding all live vaccines while you use this drug.

Vaccines are a powerful tool to prevent several serious diseases. Talk with your doctor to be sure you’re up to date on all of your vaccinations. They can help you to get fully and safely vaccinated before or during treatment with Ilumya.

The Healthline Pharmacist TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
Was this helpful?

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.