I don't mean to bother you. I am not Muslim, but I have deep respect for your faith and work and study with Muslims on an almost daily basis. I have noticed that some of my Muslim friends do not eat certain foods. Can truly necessary medications--insulin, for example--be exempt from Muslim dietary rules? I know God would never want a person to actively harm or kill him- or herself without very, very good reasons. I have learned that people who are ill or very elderly are not expected to fast during Ramadan, and people are asked to go on the hajj only if they can afford it. My true interest is the core of Islam. As a Quaker, I believe any religion that leads a person to find the love and truth within and live it with all people has something precious from which I can learn and enrich my own faith. I was just curious about the dietary laws.
In general, necessity overrides prohibition. This comes from Qur'an verses such as:
... But whoever is forced [by necessity], neither desiring [it] nor transgressing [its limit], then indeed, your Lord is Forgiving and Merciful. -- Qur'an 6:145
Then the question becomes: when is something necessary enough to override prohibition? Unsurprisingly, there's differences of opinion on the matter.
Islam Q&A describe it as:
Necessity means cases in which a person will be harmed if he does not take the haraam option, in which the harm will effect the five essentials which are: religion, life, honour, reason and wealth.
listing two conditions by Shaykh Muhammad ibn ‘Uthaymeen:
We are compelled to do it; there's no alternative.
The haram thing must meet the necessity.
But other places describe it differently, e.g. Sunnah Online.
When it comes to medication, deciding if we are compelled to do so and if the haram thing would help with the disease appropriately would require medical expertise. Generally, a trustworthy Muslim doctor should help decide:
We would also advise you to consult a trustworthy Muslim doctor; if he tells you that your case requires treatment and that there is no suitable alternative in your case apart from this type of medicine, then there is nothing wrong with you using it, in sha Allah. -- Islam Q&A