Forzest

Common use

Forzest is used for treatment of erectile dysfunctions in men. It does not act without sexual stimulation and is effective in men regardless their age or duration of the problem. Tadalafil, the active substance of this medication, is the same as in Cialis and allows blood vessels to relax and widen letting blood flow to fill cavernous bodies of the penis. This results in erection which subsides after sex.



Dosage and direction

Take Forzest at least one hour before the planned sex intercourse, the medication effects appear withing 30 minutes and continues for up to 36 hours. If you took the drug after a high fat meat like French fries or Hamburger it could take a bit longer for Forzest effects to manifestate. Do not take more than one pill of Forzest a day.



Precautions

The medication cannot be recommended in patients who were warned against sexual activity due to heart problems. Do not take the medication unless it was prescribed to you by professional health care advisor after thorough examination of your condition. Inform your doctor before to take Forzest if you have abnormal penis, including curved penis and birth defects of the penis, had coronary artery disease, arrhythmia, angina, heart attack or heart failure, hypo- or hypertension, bleeding, stomach ulcers, diabetes, hyperlipidemia (excess of lipids in the blood), sickle-cell anemia, liver or kidney failure in history. Avoid taking Forzest with grapefruit juice, alcohol, tobacco. Smoking combined with treatment by Forzest may lead to a condition called NAION (sudden optic nerve-related vision loss). Forzest should not be used in patients younger 18 years of age.



Contraindications

Forzest is contraindicated in individuals concomitantly treated with nitrates as it may lead to sudden and life threating drops in blood pressure.



Possible side effect

The most frequent adverse reactions are headache, flushing of the face and upset stomach. In rare cases temporary changes in color vision, increased sensitiveness to light or blurred vision may occur. Prolonged erections or priapism (painful erections lasting more than 6 hours) is also possible. If your erection lasts longer than 4 hours, seek for immediate medical help as it may permanently damage your penis. Aggravation of heart problems in patients with pre-existing heart disease using Cialis was reported: heart attack, stroke, irregular heartbeats. Other side effects besides those listed may appear as individual reaction to the preparation.



Drug interaction

Never take Forzest with any medication which contain nitrates for example ones to treat angina such as nitro-glycerine (in form of tablets, ointments, sprays, skin patches or pastes) isosorbide mononitrate and isosorbide dinitrate, or recreational drugs ("poppers") such as amyl nitrate or nitrite.



Missed dose

Missed dose is not supposed as this medication is taken when needed.



Overdose

Overdose symptoms are the same described as side effects. In case of suspected overdose seek for immediate medical attention.



Storage

Keep at room temperature in a dry tight container out of reach of children and pets.



Disclaimer

We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. Any specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.

Clinical Verification

Last Clinically Updated: August 15, 2026

Written By

Dr. Elena Vance, PharmD

Clinical Specialist in Neuropharmacology

Fact Checked By

Marcus Thorne, MS

Biomedical Data & FDA Label Verification

Medically Reviewed By

Dr. Arthur Campbell, MD

Board-Certified Psychiatrist (ABPN)