Tostrex – Testosterone uses, dose and side effects


2% gel


The active substance, testosterone, is a hormone that is a type of androgen.

Tostrex is given to adult men as a testosterone replacement to treat various problems caused by testosterone deficiency (male hypogonadism ). These complaints should be confirmed by two separate blood test testosterone measurements and also include clinical symptoms such as:

  • impotence
  • infertility
  • low sex drive
  • fatigue
  • Depression
  • osteoporosis caused by low hormone levels


Tostrex should only be used if hypogonadism has been confirmed by your doctor, based on your symptoms and laboratory tests. Other causes of your symptoms must have been ruled out by your doctor before starting treatment.

Only men can use Tostrex. Tostrex has not been tested in men under the age of 18 and there is limited experience in treating men over the age of 65.

Do not use Tostrex

If you:

  • are allergic to testosterone or any of the other ingredients of this medicine (listed in section 6)
  • have or are suspected of having breast or prostate cancer.

Consult a doctor or pharmacist if any of the above apply to you.

Warnings and precautions

It is necessary to have an examination before starting the treatment and then regularly during the treatment (usually once or twice a year).

If you suffer from severe heart, liver, or kidney failure, treatment with Tostrex can lead to severe complications in the form of fluid accumulation in the body which is sometimes accompanied by ( chronic ) heart failure.

Your doctor will perform the following blood tests before and during treatment: testosterone levels in the blood, and complete blood cell count.

Tell the doctor if you have high blood pressure or are being treated for high blood pressure because testosterone can cause an increase in blood pressure et.

Testosterone treatment may increase the risk of developing an enlarged prostate gland (benign prostatic hyperplasia ) or prostate cancer. Testosterone treatment can also affect the number of red blood cells you have, your blood fat profile, and your liver function.

Tell your doctor before treatment if you:

  • have swollen hands and feet
  • are overweight or suffer from a chronic lung disease, as testosterone treatment may worsen sleep apnea (temporary cessation of breathing during sleep)
  • have diabetes and use insulin to control blood sugar levels, as testosterone treatment can affect your insulin response
  • have or get epilepsy or migraines, as these conditions may worsen during treatment
  • have bone cancer, as your doctor will need to check your blood calcium levels during treatment.
  • have or have ever had blood clotting problems
    • thrombophilia (an abnormality in blood coagulation that increases the risk of thrombosis – blood clots in the blood vessels)
    • factors that increase your risk of blood clots in veins: previous blood clots in a vein; smoking, being overweight, cancer, immobility (immobility), if someone in your immediate family has had blood clots in the legs, lungs, or other organs at a young age (eg under about 50 years of age) or with increasing age. This is how you recognize a blood clot: painful swelling in a leg or sudden color change of the skin, e.g. pale, red or blue, sudden shortness of breath, sudden unexplained cough that may lead to you coughing up blood, sudden chest pain, feeling very unsteady or dizzy, severe stomach pain, sudden loss of vision. Seek medical attention immediately if you notice any of these symptoms.

Contact your doctor if you:

  • have frequent erections
  • feel irritable, nervous, or notice that you are gaining weight
  • feel sick, vomit, notice a change in skin color, or if you get swollen ankles
  • have breathing disorders, including breathing disorders during sleep.

These symptoms may mean that the dose of Tostrex is too high and your doctor may need to adjust the dose.

Contact your doctor if you notice any skin reactions at the application site, such as a burning or stinging sensation, dryness, rash, redness, or itching. If the reaction is severe, your doctor should reassess the treatment and, if necessary, discontinue it.

If you are an athlete, keep in mind that Tostrex contains the active substance testosterone, which can give a positive result in a doping test.

Tostrex should not be used to treat male sterility or impotence.

Tostrex should not be used by women because of the possible virilizing effect (such as facial and body hair, darker voice, or altered menstrual cycle).

How to avoid transferring Tostrex to other people:

It is important not to transfer the product to other people, especially women and children. Transmission occurs through close skin contact, which causes elevated testosterone levels in the other person. If the contact is repeated or takes place over a longer period, it can cause side effects such as facial or body hair, a darker voice, or a change in the menstrual cycle in women.

This transmission can be avoided by covering the application site with loose clothing, or by showering or bathing before contact.

The following precautions are therefore recommended:

  • wash your hands thoroughly with soap and water after applying the gel;
  • cover the application site with loose clothing when the gel has dried;
  • shower or bathe before situations that involve close skin contact with someone else.

To ensure your partner’s safety, you should wait at least four hours after applying Tostrex before having sexual intercourse and wear clothing that covers the application site at the time of contact or wash the application site with soap and water before sexual intercourse.

You should wear clothing that covers the application site when in contact with children to avoid the risk of transferring the gel to the child’s skin.

If you transfer testosterone gel to another person through skin contact or if someone else comes into direct contact with the gel itself, wash the contact area of ​​the other person with soap and water as soon as possible.

If Tostrex is applied to a patient by a health care provider or home care provider, they should wear appropriate disposable gloves. The gloves must be resistant to alcohol because the gel contains ethanol and isopropyl alcohol.

Contact your doctor if you notice changes in body hair, markedly increased acne, or other signs of developing male features in people not treated with Tostrex (ie female partner or children).

Other medicines and Tostrex

Tell your doctor or pharmacist if you are taking, have recently taken, or might take any other medicines, especially any of the following:

  • blood thinners
  • corticosteroids _

Also, tell your doctor or pharmacist if you are taking or have recently taken over-the-counter medicines.

Tostrex with food and drink

Tostrex is not affected by your intake of food or drink.

Pregnancy and breastfeeding

  • Tostrex is intended for use by men only.
  • Tostrex must not be used by pregnant and breastfeeding women.
  • Pregnant women should avoid all contact with skin treated with Tostrex. Tostrex can cause damage or abnormalities in the unborn child. If your partner becomes pregnant, you must follow the advice on avoiding the transfer of testosterone gel given in this section. (In the event of contact with treated skin, wash the area immediately with soap and water.)

Driving ability and use of machinery

It is unlikely that Tostrex will affect your ability to drive or use machines.

Tostrex contains butyl hydroxytoluene and propylene glycol

Butylhydroxytoluene can cause local skin reactions (e.g. contact dermatitis ) or irritation of the eyes or mucous membranes. This medicine contains up to 1400 mg of propylene glycol per dose unit, corresponding to 350 mg/g.


Always use this medicine as directed by your doctor. Consult a doctor or pharmacist if you are unsure how and when to apply gel en.

The usual starting dose is 3 g gel (contains 60 mg of testosterone ) a day. The dose can be adjusted by your doctor and the maximum dose is 4 g gel (80 mg testosterone ) per day.

Tostrex is supplied in a multi-dose container with a dosing pump that delivers half a gram of gel (10 mg of testosterone ) with each push of the pump (when the pump mechanism is fully depressed).

The first time the multi-dose container is used :

Before using the dosing pump for the first time, it must be prepared. You do this by holding the container upright and slowly pushing down the pump properly eight times. At the first press, there may not be any gel, but throw away any gel that is squeezed out. The pump only needs to be prepared before the first dose.

Administration of Tostrex:

Your doctor will inform you how many times you have to press down the pump to get the right dose of gel when the pump is prepared. The table below gives you more information about this.

Number of printsAmount of gel (g)Amount of testosterone applied to the skin (mg)

Apply gel one to clean, dry and undamaged skin once a day, at the same time each day, e.g. in the morning after you shower.

Gel one should be smeared either on the abdomen (on an area of ​​at least 10 x 30 cm) or divided in half and smeared on the inside of each thigh (on an area of ​​at least 10 x 15 cm). It is recommended that you apply Tostrex on the abdomen one day and the inside of both thighs the next day.

Application in other places should be avoided. In particular, do not apply Tostrex to the genitals.

Gently apply gel one with a finger until it has dried, then cover the area with loose-fitting clothing (eg T-shirt, shorts, pants). Wash your hands thoroughly with soap and water when you are finished.

If you intend to shower or bathe, you should do so either before applying Tostrex or wait at least two hours after application.

Two weeks after you start your medication, the doctor will take a blood test to see if your dose needs to be changed. While you are taking Tostrex, your doctor will carry out regular medical checks.

If you are responsible for having blood samples tested while using Tostrex, you must ensure that all testosterone measurements are performed by the same laboratory, due to varying assay values ​​between different diagnostic laboratories.

If you have used too much Tostrex 

If you have ingested too much medicine or if, for example, a child has ingested the medicine by mistake, contact a doctor or hospital for an assessment of the risk and advice.

If you forget to use Tostrex

Do not take a double dose to make up for a missed dose. Apply the next dose at the usual time.

If you stop using Tostrex

Always talk to your doctor or pharmacist before you stop using Tostrex.

If you have any further questions about this medicine, ask your doctor or pharmacist.


Like all medicines, this medicine can cause side effects, although not everybody gets them.

Very common side effects ( occurring in more than 1 user in 10) are skin reactions at the application site such as a burning or stinging sensation, dryness, rash, redness, or itching. These are usually mild temporary side effects of Tostrex but if they are bothersome or last more than a few days you should talk to your doctor or pharmacist as soon as possible.

Common side effects ( affects 1 to 10 users in 100) are: swelling of the hands or feet, high blood pressure, prostate changes (including increased blood levels of a protein called a prostate-specific antigen, which is produced by the prostate ), increased body hair, breast enlargement, increased number of red blood cells (measured in blood tests). An increase in the number of red blood cells, hematocrit (the percentage of red blood cells in the blood), and hemoglobin (the component of red blood cells that transport oxygen) are identified with regular blood tests.

Other known side effects associated with testosterone treatment are hair loss, dandruff, acne, jaundice (liver problems that can sometimes be accompanied by a yellowing of the skin and the whites of the eyes), abnormal liver function tests, nausea, altered sexual desire, more frequent erections, difficulty urinating, depression, nervousness, hostility, weight gain, muscle cramps or muscle pain, fluid retention, swollen ankles, sleep apnea and, rarely, painful and persistent erections. Decreased sperm production and decreased testicular size may occur at high doses. Long-term testosterone administration can cause changes in salt levels ( electrolytes) in the body.

There is no convincing evidence that testosterone replacement in hypogonadal men causes prostate cancer. However, testosterone treatment should be avoided in men who are known or suspected to have prostate cancer.

Hyperglycaemia (too high a blood sugar level) has been reported in cases involving 2 people who had diabetes mellitus.

If any side effects get worse or if you notice any side effects not mentioned in this information, contact your doctor or pharmacist as soon as possible.


Keep this medicine out of the sight and reach of children.

Use before the expiry date stated on the label after EXP. The expiration date is the last day of the specified month.

Store at a maximum of 25ºC.
Store protected from cold, do not freeze.
Store container upright after opening.

Medicines must not be thrown into the drain or among the household waste. Ask the pharmacist how to dispose of medicines that are no longer used. These measures will help to protect the environment.


Contents declaration

  • The active substance is testosterone. One gram of gel contains 20 mg of testosterone.
  • Other ingredients are propylene glycol, anhydrous ethanol, isopropyl alcohol, oleic acid, carbomer 1382, trolamine, butylhydroxytoluene (E321), purified water, and hydrochloric acid (for pH adjustment).

Appearance and package sizes of the medicine

Tostrex is a clear gel, which varies from colorless to pale yellow.

Tostrex is delivered in containers of 60 grams of gel each. The containers are equipped with a dosing pump that provides a set amount of gel.

A carton may contain one, two, or three multi-dose containers of gel. Not all pack sizes may be marketed.

Marketing Authorisation Holder

Kyowa Kirin Holdings BV

Bloemlaan 2

2132NP Hoofddorp


Information provided by:

Kyowa Kirin AB


Tel.: 08-50 90 74 10


PHARBIL Waltrop GmbH
I’m Wirrigen 25
45731 Waltrop

This medicine is approved in the European Economic Area under the names:

Austria, Denmark, Finland, Germany, Greece, Hungary, Ireland, Netherlands, Norway, Poland, Portugal, United Kingdom: Tostran

Italy, Sweden: Tostrex

Belgium, Spain, Luxembourg: Itnogen

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