The Messenger of Allah ﷺ prohibited unclean medicine.  

نَهَى رَسُولُ اللَّهِ ﷺ عَنِ الدَّوَاءِ الْخَبِيثِ  

When a physician consulted the Prophet ﷺ about putting frogs in medicine, he forbade him to kill them.  

أَنَّ طَبِيبًا سَأَلَ النَّبِيَّ ﷺ عَنْ ضِفْدَعٍ يَجْعَلُهَا فِي دَوَاءٍ فَنَهَاهُ النَّبِيُّ ﷺ عَنْ قَتْلِهَا  

If anyone drinks poison, the poison will be in his hand (on the Day of Judgement) and he will drink it in Hell-fire and he will live in it eternally.  

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ حَسَا سُمًّا فَسُمُّهُ فِي يَدِهِ يَتَحَسَّاهُ فِي نَارِ جَهَنَّمَ خَالِدًا مُخَلَّدًا فِيهَا أَبَدًا  

Wa'il said: Tariq ibn Suwayd or Suwayd ibn Tariq asked the Prophet ﷺ about wine, but he forbade it. He again asked him, but he forbade him. He said to him: Prophet of Allah, it is a medicine. The Prophet ﷺ said: No it is a disease.  

عَنْ أَبِيهِ ذَكَرَ طَارِقَ بْنَ سُوَيْدٍ أَوْ سُوَيْدَ بْنَ طَارِقٍ سَأَلَ النَّبِيَّ ﷺ عَنِ الْخَمْرِ فَنَهَاهُ ثُمَّ سَأَلَهُ فَنَهَاهُ فَقَالَ لَهُ يَا نَبِيَّ اللَّهِ إِنَّهَا دَوَاءٌ قَالَ النَّبِيُّ ﷺ لاَ وَلَكِنَّهَا دَاءٌ  

The Prophet ﷺ said: Allah has sent down both the disease and the cure, and He has appointed a cure for every disease, so treat yourselves medically, but use nothing unlawful.  

قَالَ رَسُولُ اللَّهِ ﷺ إِنَّ اللَّهَ أَنْزَلَ الدَّاءَ وَالدَّوَاءَ وَجَعَلَ لِكُلِّ دَاءٍ دَوَاءً فَتَدَاوَوْا وَلاَ تَدَاوَوْا بِحَرَامٍ