QUESTION:

As Salaamu Alaikum,

I am writing with deep concern and would sincerely appreciate a clear ruling according to the Ḥanafī madhhab, as this matter is causing me significant anxiety.

I am diabetic, with a condition that is described as a combination of Type 1 and Type 2 diabetes. For the past 7 years, I have been using a continuous blood glucose monitoring system called Free Style Libre. This is a small sensor that is inserted under the skin of my upper arm and continuously records my blood glucose levels 24/7. My medical team depends on this detailed data to monitor patterns and adjust my insulin dosage. My diabetes is currently well controlled using this method.

Each sensor works for 2 weeks, and I receive 2 per month. Once applied, it cannot be removed and reapplied. If I were to take it off, I would have to replace it with a new sensor.

Because the sensor adheres to the skin and covers a small area, water does not reach the skin directly beneath it during ghusl. My question is: would my ghusl be valid in this situation? I am extremely worried about the validity of my purification and prayers.

If using this device presents a problem from a fiqh perspective, the only alternative would be to return to finger-prick testing. However, that method provides only isolated snapshot readings at the moment of testing, rather than continuous and comprehensive data. As a result, it does not offer the same level of insight into daily fluctuations in blood glucose levels.

Although I have not undertaken a detailed comparison with my medical team, this continuous monitoring system has been relied upon for years to guide precise insulin adjustments and maintain stable control. I am therefore genuinely concerned that reverting to finger-prick testing alone could compromise the quality of my glucose management and, in the long term, negatively affect my health.

 

ANSWER:

Wa Alaikum As Salaam,

Based on the explanation given of your situation, it is evident that you have a valid reason for using this sensor. On account of this, the Free Style Libre Sensor that is attached to your skin falls under ‘need and necessity’ for medical reasons, and it would be permissible to have it attached to your body while taking a ghusl.

Seeing that this covers a small area of the body which prevents water from reaching the skin, you will need to take your wet hand and wipe/pass it on the small sensor in place of the actual washing of the skin under the sensor. Some Jurist experts have stated that you must pass water over the sensor (let the water flow on it), instead of wiping it with your wet hands, and this is the most precautious opinion. When you do this, your Ghusl will be valid.

(Hashiya At Tahtawi Ala Maraqi Al Falah Pg. 137)

 

And Allah Knows best

Mufti Waseem Khan

3/2/2026