I analyzed hormone levels in Saliva for 5 years from 2000 to 2005. I'm not sure how much has changed in the accuracy and detection ability since then, but i would lean toward bloodwork. There are so many factors that can throw off results in saliva sampling. You have to follow a strict ingestion schedule before collection, because numerous foods can skew results, such as garlic, chocolate, etc. They may be much improved in the past three years. If not, i would stick with blood tests.