Testosterone is a naturally occurring male hormone necessary for many processes in the body.

Natesto (for use in the nose) is used to treat conditions in men that result from a lack of natural testosterone.

Testosterone will not enhance athletic performance and should not be used for that purpose.

Natesto may also be used for purposes not listed in this medication guide.

You should not use Natesto if you have prostate cancer or male breast cancer.

Natesto should not be used by a woman. Testosterone can cause birth defects in an unborn baby.

Misuse of testosterone can cause dangerous or irreversible effects. Never use more than your prescribed dose. Do not share this medicine with another person.

Follow all directions on your prescription label. Never use Natesto in larger amounts, or for longer than prescribed.

Misuse of testosterone can cause dangerous or irreversible effects, such as enlarged breasts, small testicles, infertility, high blood pressure, heart attack, stroke, liver disease, bone growth problems, addiction, and mental effects such as aggression and violence.

Do not share Natesto with another person.

Do not take by mouth or use on the skin. Natesto is for use only in the nose.

Read all patient information, medication guides, and instruction sheets provided to you. Ask your doctor or pharmacist if you have any questions.

Blow your nose gently before using Natesto gel.

Wash with soap and water if the gel gets on your hands or skin while using it.

While using Natesto, you may need frequent blood tests.

Use Natesto regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

Do not share this medicine with another person.

Store at room temperature away from moisture and heat.

You should not use this medicine if you are allergic to Natesto gel, or if you have:

• prostate cancer; or

• male breast cancer.

To make sure Natesto is safe for you, tell your doctor if you have:

• a history of problems with your sinuses or nasal passages;

• a history of surgery on your nose or sinuses;

• a broken nose (now or within the past 6 months);

• a deviated septum (crooked nose);

• breast cancer, prostate cancer;

• enlarged prostate, urination problems;

• sleep apnea (breathing stops during sleep);

• heart disease, history of heart attack or stroke;

• a history of blood clots; or

• liver disease or kidney disease.

Older men who use Natesto may have an increased risk of prostate enlargement. If you are over 65, talk with your doctor about your specific risk.

This medicine should not be used by a woman. Testosterone can cause birth defects in an unborn baby. A pregnant woman should avoid coming into contact with Natesto gel. If contact does occur, wash with soap and water right away.

Natesto is not approved for use by anyone younger than 18 years old.

Apply the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next dose. Do not use extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Avoid using other medications in your nose, unless your doctor tells you to.

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Natesto may cause serious side effects. Stop using Natesto and call your doctor at once if you have:

• increased urination (many times per day), loss of bladder control;

• painful or difficult urination;

• swelling, rapid weight gain, shortness of breath during sleep;

• breast pain or swelling;

• chest pain or pressure, pain spreading to your jaw or shoulder;

• painful or bothersome erections;

• nasal problems--runny or stuffy nose, sneezing, nosebleed, nose pain or dryness, scabs inside or around your nose;

• liver problems--nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

• signs of a blood clot in the lung--chest pain, sudden cough, wheezing, rapid breathing, coughing up blood; or

• signs of a blood clot in your leg--pain, swelling, warmth, or redness in one or both legs.

Common side effects of Natesto may include:

• nasal problems;

• sore throat; or

• headache.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all your current medicines and any you start or stop using, especially:

• insulin;

• a blood thinner (warfarin, Coumadin, Jantoven); or

• a steroid such as methylprednisolone, prednisone, and others.

This list is not complete. Other drugs may interact with testosterone nasal, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.