Any of you out there have low tpmt levels and allowed to stay on 6mp. I am very nervous, this morning I got a call from my GP saying my TPMT levels came back low which put me on a high risk of being too supressed on this drug. I had the test sometime in late january, it took ages to come back. I have read about it and it says low tpmt levels means that the drug is toxic to you. I don't want to stay on this if this is the case. The GP contacted my GI and he says to take bloods every 2 weeks for the next 3 months and monitor by white blood cells but isn't this blood test a sure indicator that the drug is unsuitable.