This private blood test measures your International Normalised Ratio, used to monitor blood clotting, most commonly for people taking warfarin. The test costs £39.38, plus a £50 blood-draw fee, with results usually available in 1 day.
You can walk in or book online at 117a Harley Street, seven days a week.
Written by Mr Stephen Lingam. Reviewed by Dr Mohammad Bakhtiar (GMC 4694470) on 28/09/2026.
It measures your International Normalised Ratio, used to monitor blood clotting, most commonly for people taking warfarin.
The test costs £39.38. A separate £50 blood-draw fee applies.
Results are usually available in 1 day.
No GP referral is needed. You can walk in or book online.