More Laboratories Where You Can Get Antibodies Checked
The Doctors Laboratory (the biggest private laboratory in the UK) do TSH Receptor Antibodies (TSI is one type of these). You have to have a doctor’s request you cannot order yourself.
Medicheks (who I believe use The Doctors Laboratory as their lab) also offer this service, but the markup is huge on the price (199). The advantage is that you don’t need a doctor’s request and the result if sent to you.
About TSH Receptor Antibodies.