"Doctor" Endorsed Commericals

As I was laying in bed watching tv I came across a commerical for a "new" acne treatment. During the commerical a short clip was integrated with a doctor stating their degree and endorsing the product. The production on this commercial seemed low budget and the doctor seemed to only care about the pay check resulting from the endorsement. With so many new products being introduced with endorsement's how can we seperate genuinely backed products as opposed to those that arent?