Sending it out of the United States, only within real limits. USPS Publication 52 admits a drug into international mail only if it is already mailable inside the US and the destination country itself does not prohibit it, and it excludes controlled substances from international mail entirely, with no exception listed. Bringing medicine into the United States by mail runs through a separate, narrower gate: the FDA's personal importation policy, which tolerates an unapproved drug only for a serious condition without adequate US treatment, in roughly a three-month supply, affirmed in writing by the person taking it. Neither direction reopens the door that domestic mail already keeps shut on one private person mailing another person's prescription. Sources read 2026-08-28.
The US side decides what may leave. The destination country decides what may arrive. A shipment has to clear both.
Publication 52 governs international mail in its own chapter, separate from the domestic drug rule our medication guide already covers, and it puts the rule for ordinary drugs in one short section.
“Drugs admissible in domestic mail (refer to Chapter 4) are also acceptable in international and APO/FPO/DPO mail, provided the destination country or military or diplomatic Post Office does not prohibit their entry.”
USPS Publication 52, Chapter 6, Section 634 Drugs, pe.usps.com, read 2026-08-28.
Controlled substances get their own section immediately after it, and the wording is not conditional the way section 634 is.
“Controlled substances are not permitted in international mail.”
USPS Publication 52, Chapter 6, Section 635 Controlled Substances, pe.usps.com, read 2026-08-28. The same section adds that controlled substances addressed to APO/FPO/DPO destinations are subject to the prohibitions in DMM 703.2.3 or 703.3.2, and to Department of Defense conditions published separately.
| Category | Domestic condition it inherits | What section 634 or 635 adds |
|---|---|---|
| Over-the-counter medicine | Mailable by any sender under section 453 | Also acceptable internationally only if the destination country does not prohibit it |
| Prescription medicine, non-controlled | Sender must be a pharmacist, practitioner or other authorized dispenser under section 453 | Same destination-country condition applies on top of the domestic sender rule |
| Controlled substances | Sender and addressee must both be DEA-registered or exempt | Not permitted in international mail at all, regardless of registration on either end |
The practical read: international mail never loosens the domestic rule, it only adds a second condition on top of it. A pharmacy that is licensed to mail a prescription across state lines still has to check whether the receiving country accepts it before the international rule is satisfied.
The reverse direction is not a USPS mailability question at all — it is an FDA import question, and the agency's default position is blunt.
“In most circumstances, it is illegal for individuals to import drugs or devices into the U.S. for personal use because these products purchased from other countries often have not been approved by the FDA for use and sale in the U.S.”
FDA, Personal Importation, fda.gov, page last updated 08/18/2025, read 2026-08-28.
The same page lays out a personal importation policy under which the FDA does not intend to act against a shipment, provided every condition below is met.
| Condition | What it requires |
|---|---|
| Purpose | Treats a serious condition without adequate treatment already available in the United States, or the product carries no known significant health risk |
| No promotion | The product is not commercialized or promoted to people living in the United States |
| Risk | The product does not represent an unreasonable risk |
| Affirmation | The person receiving it confirms in writing that it is for personal use |
| Quantity | Generally no more than about a three-month supply, and the importer either names their US doctor with an address or shows the treatment was started abroad |
Read the table for what it is: a description of when the FDA has chosen not to act, not a right anyone can invoke at the border. Customs and Border Protection and the FDA can still hold, inspect or destroy a parcel that fails any one of these conditions, and a foreign national mailing or carrying medicine into the country falls under the same roughly three-month ceiling.
Every international question above rests on the same domestic foundation our medication guide covers in full: a private person cannot mail somebody else's prescription, over-the-counter medicine is open to any sender, and a controlled substance needs a DEA-registered or exempt party on each end. International mail layers a destination-country condition onto the outbound side and a narrow personal-use exception onto the inbound side; it does not loosen the underlying rule in either direction, and section 635's flat international ban on controlled substances makes the outbound side stricter, not looser.
UPS and FedEx are not bound by USPS Publication 52, but both run their own healthcare-account and DEA-registration programs for pharmaceutical shipments, domestic or international, layered under the same underlying drug law. Our FedEx-specific guide covers that carrier's international pharmaceutical rules, including the FDA approval question a shipment into the US has to clear at that carrier's own counter.
Postal rules, FDA policy and every destination country's own import law are revised without notice. Treat the wording above as what these sources held on the date shown, and check the current version and the specific destination country's listing before mailing anything across a border.
Only within limits USPS sets in Publication 52. A drug already mailable inside the US is also acceptable internationally, but only if the destination country itself does not prohibit it, and controlled substances are barred from international mail outright regardless of what either country would otherwise allow.
Rarely, and not as a routine option. The FDA's personal importation policy tolerates it only for a serious condition without adequate US treatment, in roughly a three-month supply, with the recipient affirming in writing that it is for their own use, and the policy is enforcement discretion rather than a right to import, so a shipment can still be held at the border.
Not through USPS. Publication 52 section 635 states plainly that controlled substances are not permitted in international mail, a flatly stricter rule than the domestic one, which at least allows DEA-registered senders and addressees.
No special federal paperwork on the US side beyond an accurate customs declaration, but the destination country's own import rules still apply, and those vary by country and by ingredient — a decongestant with pseudoephedrine, for instance, is controlled in some countries that never restrict it at home.
No. Medicine, prescriptions and supplements are declined at the quote stage regardless of destination, the same policy our domestic medication guide describes in full.