Sarcosine quality between two suppliers

I tried brainvitaminz’s sarcosine. It works for reducing my symptoms. But I don’t live in USA. So brainvitaminz send sarcosine by USPS mail service and it can not trace after departing USA. So I searched Amazon. I found Nootropics depot’ s Sarcosine. And it can trace before arriving to me. So I wonder the quality of sarcosine between two suppliers. Are the quality of their
Sarcosine same? I want your opinion.