It is difficult
    for him to fast and he wants to take some medication to reduce his desire
Question

                My question is regarding the suppression of
    sexual desires. In this country, at this age, it is very difficult not to get aroused
    several times a day. I hope you can understand. This causes stress while praying because a
    drop or two may come out and during the whole prayer I am worried about it. Also, it
    delays my performing the prayer. You said masturbation is not allowed. And you mentioned
    fasting. Due to my circumstances fasting voluntary fasts regularly is not feasible as it
    makes me too tired to study and concentrate. Also I am not able to marry now. This
    situation might continue for years if Allah grants me that long a life. Can I therefore
    castrate myself or take drugs that suppress sexual desires? I think the good that such a
    measure would do will outweigh the harm and make me steadfast in my prayer and
    concentration.But I wanted your advice before I take any steps .
Praise be to Allah.Fasting is not only a remedy, it is also a purification of
    the soul and a means of earning reward and the pleasure of Allaah. It is also a striving
    against one’s desires. With a little patience and the hope of earning reward, one can
    get used to fasting. Allaah says (interpretation of the meaning):
“Observing As-Sawm (the fasting) is prescribed for you as it was
    prescribed for those before you, that you may become Al-Muttaqoon (the pious)”
    [al-Baqarah 2:183]
In the Tafseer of this aayah it was said that according to one opinion,
    the phrase “that you may become al-muttaqoon” means: that you may stay
    away from sin, because fasting is more of a deterrent and is more effective in keeping one
    from falling into sin. This is one of the meanings of the hadeeth, “Let him fast for
    that will be a protection for him.” Many people think that this is because fasting
    weakens the body and thus weakens desire. Even if that is the case, it is in addition to
    the fact that fasting motivates a person to keep away from anything that he fears may
    affect him adversely, either because of the blessing of the fast itself or because if the
    one who is fasting has to refrain from food and drink that are permissible, it is even
    more appropriate that he should keep away from things which are forbidden.
Fataawa al-Subki, part 1: al-Siyaam: Hifz al-Siyaam
    ‘an Fawt al-Tamaam
When young people who are unable to marry were commanded to fast, this is
    a sign of the wisdom and insight of the Lawgiver. It is clear that fasting has an effect
    in this regard and that it helps to control desire and reduce provocation.
With regard to your question about taking medication that can reduce
    desire, there is no reason why you cannot take some herbal extracts etc. to control your
    desires, so long as they are not harmful in any way. But this will not be of much help if
    you do not do some acts of worship to fill your time and other activities to use up your
    physical energy, such as Da’wah activities and helping those in need. Also reduce
    your intake of rich foods, do some sports activities, keep yourself busy with useful
    things, and make yourself a schedule that will use up your excess physical energy. Do not
    forget that it is also very important to keep away from sources of provocation. Be
    optimistic and do not think that you will remain in this situation for many years. May
    Allaah make it easy for you to marry soon. May He protect us and you from evil and guide
    us to the Straight Path.