Is it British Dragon or C&K? Although their tabs look exactly alike, nobody knows for sure if they come from the same place.
For example, C&K's 50mg anavar tested out to have 0mg of anavar, and they didn't test for any other compounds. Most people think it's winny. On the other hand, his 5mg tested out great.
I've never heard anything bad about British Dragon's higher dose var, so I don't know if they're the same.
You really shouldn't have to worry since you're using the 5mg's, but that bunk 50mg shit is some shady business.