Precautions in the instructions for drugs. In general, they do not harm health, they are taken for years without consequences. Some report that the effect is temporary, for several months.
Also - other drugs, castration, sublimation (active activity), cognitive therapy. The last two points do not reduce libido, but allow it to be controlled.
The Apostle Paul generally advised to rip out the tempting organ (an eye squinting at girls, for example). A lot of people, especially religious people, tried to suppress libido. Hence all these ascetics, monks and eunuchs, their flesh also prevented them from thinking about high things. Often these were some wild methods, like self-harm. This is well described by Vasily Rozanov in the book People of the Moonlight. A less radical method would be to take a vow of celibacy and / or become a monk. With an environment of chastity and an understanding environment, it is much easier to pacify the flesh. Otherwise, if you are not ready for monasticism and asceticism with spiritual work, the world with its “selling sex” coupled with constant self-flagellation will cause you frustration and it will simply be harder to live. But the goal was the opposite, to make it easier? Therefore, the only way out, I think, is not to shove against the tank of evolution and find yourself a permanent partner, in a long-term relationship a calmer attitude to sex and in general, this is a more harmonious way to negotiate with Mother Nature.
By forcing yourself and nothing else.
Make yourself think that it hurts your life (it's up to you).
Apparently, the question is in a broader sense, in other words, the problem is not only in your desires reduce the desire for sex (like sexual intercourse between a boy and a girl), but also force yourself not to indulge in self-abuse (my assumptions).
Personally, as an advice to you, try to fill your free time with deeds.
Read, write, fantasize, draw, do everything that can distract from these thoughts.
First, Homo Sapiens have no instincts. Generally. Including sexual desire is not instinctively, but is formed in the course of education. Secondly, it is easiest to reduce libido by physical fatigue. Work hard physically from morning to evening, and you won't have any "wishlist". But thirdly, it's harmful.