As per recommendations from folks here I sent,for a Blue Horizon blood test kit. Bearing in mind it was 2 weeks since being starting T3 I chose the finger prick test. I did the test exactly as recommended and barely got any blood out. As it was insufficient for testing Blue Horizon sent me another kit and as nurse at GP surgery agreed to draw blood I had it done there today. This is now 3 weeks on T3. The nurse was unable to draw blood from arm on two attempts and eventually managed on my hand, although it was extremely slow coming. I have never had a problem with blood tests in the past, and have had many of them. Is this likely to be a side effect of the T3?