Does taking a benzodiazepine (Klonopin - .5mg) before getting tested for TSH, free T3, and free T4 effects the results? I usually take about 1mg/day of Klonopin and took .5mg about one hour before getting my blood drawn. My results for each turned out, more or less, right in the middle of their reference range, even though I show many of the symptoms of Hypothyroidism.