Is the person who takes medication to reduce sexual desire, which led him to approach adultery, sinful?

There is no harm in using stimulating medications with controls, including: the need for them, and that they be prescribed by a trusted doctor. The treatment for excessive lust is marriage, or fasting for those who cannot marry, along with staying away from provocations. What happened regarding the preliminaries of zina (fornication/adultery) is a grave mistake and a heinous evil. The perpetrator must offer sincere repentance, regret, and a firm resolve not to repeat it. This is aided by abandoning the footsteps of Satan, avoiding places of temptation, staying away from everything that arouses lust, seeking help from Allah, contemplating Allah's blessings, remembering death and the Afterlife, avoiding the company of disobedient people, being keen on the company of the righteous, attending gatherings of knowledge and remembrance, frequent remembrance and supplication, occupying free time with beneficial activities, and engaging in sports. If the wife is not sufficient to satisfy desire, then polygyny up to four wives is permissible. If one cannot practice polygyny, and the wife is not sufficient, then one must stop the medication that causes excessive lust leading to sin, because warding off evil is given precedence over gaining benefits.