Yes I work out a lot and really like the ZMA from Biotest but you must think what you are doing first Thinning... ZMA raises test levels which in turn becomes DHT when it is in excess which will lead to more hairloss.
I do not believe any product that aids in weighlifting by increasing Test levels is beneficial to hair growth, trust me I have tried them all and lost.
The best is new Creatine products like V-12, least for me anyway.