I have a blue and white capsule pill with absolutely no imprint on it. I think it may have came from

Destroy it

Be careful with anything coming from Mexico... a lot are saying this is an antibiotic, but I have some blue and white capsules with no imprint from Mexico and they are generic soma!

I wouldn't take anything without a script from a reputable licensed physician that's been filled at a reputable pharmacy. I also only take medications approved by the FDA or an equivalent agency in certain foreign countries.
Best regards,
Wildcat

Its antibiotics my grandma gets those from mexico all the time

It is impossible to ID any pill online without an imprint - sorry. All Rx and OTC drugs in the US are required by the FDA to have an imprint.

Your pill could be one of the following: diet, energy, herbal, vitamin, illicit or foreign.

I realise you said it came from Mexico, please remember though that capsules are able to be filled with anything, so identification of an unmarked one is impossible without testing.