Short answer
It depends on the source. Stem cells from your own body, a consenting adult donor, or umbilical cord blood are allowed for treatment. Using embryos created for research, or from an abortion done without a valid reason, is not allowed. Spare IVF embryos are disputed. Follow a qualified doctor and ask a mufti about your case.
Treatment with one's own cells is permitted. Taking cells from another person is judged like blood donation when the body replaces them, as with bone marrow and blood stem cells, and is permitted for need. Creating embryos in order to destroy them is not permitted.
The four schools agree on this.
Explanation
Stem cells are cells that can grow into other kinds of cells. They are used in bone marrow transplants for leukaemia and other blood disorders, and are being studied for many other diseases. Saving and healing life is a great good: Allah says whoever saves one life, it is as if he saved all mankind.
Scholars judge stem cell treatment by where the cells come from:
- Your own body (blood, bone marrow, fat): allowed, like any treatment.
- An adult donor, as in a bone marrow or stem cell transplant: allowed by many scholars who otherwise restrict organ donation, because the body replaces these cells, as it does blood. See donating blood.
- Umbilical cord blood and placenta tissue after birth: allowed with the parents' consent. Private or public cord blood banking is permitted.
- A miscarriage or an abortion done for a valid medical reason: allowed by some councils with consent.
- Embryos made for research, by cloning or otherwise: not allowed.
- Spare IVF embryos donated by the couple: scholars differ. The Muslim World League council allowed it with the couple's consent; others, including many Hanafi muftis, do not. See leftover IVF embryos.
The Islamic Fiqh Council of the Muslim World League issued a resolution along these lines, permitting stem cells from lawful sources and forbidding those from unlawful ones.
Be cautious with private clinics selling unproven stem cell "cures". Paying for a treatment that has no real evidence can harm you and waste your wealth. Follow a qualified doctor's advice and use regulated treatment.
Ask a mufti about your own case. This answer explains the general ruling. When the details of your situation matter, as they do here, ask a qualified mufti and give them the full facts. Where to ask a scholar.
The evidence
Quran, Surah Al-Maaida 5:32
مِنْ أَجْلِ ذَٰلِكَ كَتَبْنَا عَلَىٰ بَنِىٓ إِسْرَٰٓءِيلَ أَنَّهُۥ مَن قَتَلَ نَفْسًۢا بِغَيْرِ نَفْسٍ أَوْ فَسَادٍۢ فِى ٱلْأَرْضِ فَكَأَنَّمَا قَتَلَ ٱلنَّاسَ جَمِيعًۭا وَمَنْ أَحْيَاهَا فَكَأَنَّمَآ أَحْيَا ٱلنَّاسَ جَمِيعًۭا ۚ وَلَقَدْ جَآءَتْهُمْ رُسُلُنَا بِٱلْبَيِّنَٰتِ ثُمَّ إِنَّ كَثِيرًۭا مِّنْهُم بَعْدَ ذَٰلِكَ فِى ٱلْأَرْضِ لَمُسْرِفُونَ ﴿٣٢﴾
Because of that, We decreed upon the Children of Israel that whoever kills a soul unless for a soul or for corruption [done] in the land - it is as if he had slain mankind entirely. And whoever saves one - it is as if he had saved mankind entirely. And our messengers had certainly come to them with clear proofs. Then indeed many of them, [even] after that, throughout the land, were transgressors.
Treatment that saves life is greatly rewarded.
Quran, Surah Al-Israa 17:70
۞ وَلَقَدْ كَرَّمْنَا بَنِىٓ ءَادَمَ وَحَمَلْنَٰهُمْ فِى ٱلْبَرِّ وَٱلْبَحْرِ وَرَزَقْنَٰهُم مِّنَ ٱلطَّيِّبَٰتِ وَفَضَّلْنَٰهُمْ عَلَىٰ كَثِيرٍۢ مِّمَّنْ خَلَقْنَا تَفْضِيلًۭا ﴿٧٠﴾
And We have certainly honored the children of Adam and carried them on the land and sea and provided for them of the good things and preferred them over much of what We have created, with [definite] preference.
Human life, including early human life, must not be treated as raw material.
Sahih al-Bukhari 5678
Sahih... ما أنزل الله داء إلا أنزل له شفاء ...
"Allah has not sent down any disease without sending down a cure for it."
Seeking new treatments is encouraged.
Where the ruling is recorded
- Resolutions of the Islamic Fiqh Council of the Muslim World League, Resolution on stem cells. Permits stem cells from lawful sources such as adults, cord blood and lawful miscarriages, and forbids deliberately created embryos.
- al-Fatawa al-Hindiyya, Kitab al-Karahiyya, chapter on treatment. Treatment is permitted, and human parts are treated with honour.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.