Neem is a traditional herd herb used for many veterinary and human health applications. However, much of the benefits (and adverse effects are anecdotal.
The point is that which therapeutic effect you want to test the neem for? Neem (Azadirachta indica) has been tested for its efficacy for various indications. Try to google your requirement. Some of them are given below:
-https://www.ncbi.nlm.nih.gov/pubmed/27794147
-Article Antimicrobial efficacy of endodontic irrigants from Azadirac...
-Article Potential of neem (Azadirachta indica L.) for prevention and...