Traveling to Mexico. How much prescription meds can be brought into US at one time? What are the limits?

antibiotics...

You can bring in up to a three month supply, but be warned: You MUST have a valid prescription written by a doctor who is licensed in the U.S., and you MUST have that prescription with you when you enter the country. If you don't, your meds will be seized and the chances of getting them back are not very good.

hmmmm crossing by land? theyve never checked me...

Whatever your prescription indicates. Some antibiotics can be purchased in small quantities over the counter. Three months supply is the rule. Ask the pharmacist.

Hi, I'm Mexican and currently live in the US. The first time I came I brought A LOT of medicines.... over the counter and prescription (well, you would need a prescription here but you don't in Mexico). Every time I go back for vacation I bring more to replace the ones I've used, if any. I've never had trouble crossing them. I just put some in each piece of luggage I check and that's it. Now, I bring different meds to cure different things.... if I only brought a lot of the same that might be trouble because they might think I want to sell them.

90 day supply for personal use is what the FDA has told customs is OK