[The ruling of the Sacred Law on cosmetic operations]

The answer – and Allah is the Patron of success – is that the Wise Lawgiver has forbidden that a person cause himself or another pain that harms him, without a reason of illness or the like; and this is the basic principle.
There is no disagreement that cauterization with fire is permissible in the case of an illness that necessitates it, and likewise cupping and bloodletting, and cutting off a limb afflicted by a known disease, and carrying heavy loads, and plucking the armpit hair, and prescribed punishments (ḥudūd), and disciplinary measures, and the like.
Accordingly, the basic principle is that causing pain to the body for the purpose of adornment is forbidden; so it is not permissible for a Muslim to cause himself pain by a cosmetic operation except in the manner we have mentioned, in that which has been specified by the evidence.
And it has come in an authentic ḥadīth that the Messenger of Allah (May Allah bless him and his family and grant them peace) cursed the woman who tattoos and the woman who seeks to be tattooed… to the end of the ḥadīth. Tattooing is: making a wound in the face or the like, then putting kohl in the wound; when the wound heals, a black mark appears in its place in the shape of an adornment. In this authentic narration there is proof for what we have mentioned.
If it is said: If the effective cause (ʿillah) in the prohibition of cosmetic operations is the painful harm, then the physician, before carrying out the operation, anaesthetizes the place of the operation such that the person does not feel any pain, then after the operation he gives him treatment whereby he does not feel pain until he recovers; so, in that case, there is no reason for prohibition.
What strengthens this further is that, in this same mentioned ḥadīth, there has come the curse of the woman who plucks and the one who seeks to be plucked, and al-namṣ is plucking the hair of the pubic region; yet the scholars have allowed its plucking if it is smeared with depilatory paste (nūrah), because the pain of plucking with nūrah is removed, so it appears that the prohibition revolves with pain, in existence and non-existence.
We say: We have mentioned that the effective cause is painful harm; thus harm (al-adha) is a qualifier of pain, and they have said that the ruling attaches itself to the qualifier, so the effective cause in reality is harm, and harm is injury.
And even if the pain is removed by anaesthetic, the surgical operation cannot be separated from harm and injury after the operation; everyone to whom a surgical operation has been carried out in any part of his body knows this.
As for plucking the hair of the pubic region with nūrah and the like, it does not result in any harm or any injury in the future, unlike surgical operations.
- Regarding His saying, Exalted: “and I will command them so they will change the creation of Allah” [al-Nisāʾ:119], what I see in its explanation is that what is meant is changing the rulings concerning Allah’s created things; for that is what in fact occurred from the disbelievers among the children of Adam: by his (Satan’s) seduction of them, they declared lawful what Allah had forbidden, and declared forbidden what Allah had made lawful. Examples of this are many. And He, Exalted, has said: “And do not say about what your tongues assert of untruth, ‘This is lawful and this is unlawful,’ to invent falsehood about Allah. Indeed, those who invent falsehood about Allah will not succeed.” [al-Naḥl:116].

Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.2