The title says three tiers(Prescription, OTC, Supplement). There are actually four, and the one most people don’t know about is the reason some familiar products turn up in convenience stores rather than pharmacies.
Understanding the categories explains where to look, what claims a product may carry, and why something you bought easily at home is behind a counter here.
The four categories
Korea sorts these products by what they’re for and how strongly they act, not by what’s in them.
Prescription drugs (전문의약품) — require a doctor’s prescription, dispensed at pharmacies.
Over-the-counter drugs (일반의약품) — intended for treating or preventing disease, with efficacy and safety assessed and approved by the MFDS. No prescription needed, but pharmacy only[1].
Quasi-drugs (의약외품) — products that help with treatment or prevention but whose effects on the body are minor or not direct compared with drugs[1]. No prescription, and crucially sold in ordinary retail including convenience stores and online[1].
Health functional foods (건강기능식품) — ingredients whose functionality and safety were recognised, carrying the mark and approved wording covered in an earlier post.
The quasi-drug tier is the one that surprises newcomers. It’s where sanitary products, masks, bandages, toothpaste, hand sanitiser and insecticides sit[1] — and also the fatigue tonics and liquid digestives sold at convenience store counters[1].
The category that catches people out
Here’s the practical trap.
Some vitamin and mineral products are classified as over-the-counter drugs rather than health functional foods. When that happens, they cannot be sold online and are available only at pharmacies[1].
The distinction is about claims, not contents. An OTC nutrient product has had its efficacy approved by the MFDS for treating or preventing disease — which is precisely what a health functional food may never claim[1].
So two bottles containing similar nutrients can sit in different regulatory universes. One is searchable on an e-commerce platform; the other requires a trip to a pharmacy. And as covered in the interactions post, the pharmacy one is no less relevant to your total intake.
Convenience stores carry a defined list
Since 2012, a limited set of OTC medicines can be sold outside pharmacies under the designation 안전상비의약품 — safety household medicines.
Two things worth knowing.
The list is fixed and short. It’s managed as a specific designated list rather than being open-ended[2].
The convenience store versions differ from pharmacy versions. They differ slightly in ingredients and dosage from the equivalent OTC products sold in pharmacies[1].
That second point matters if you’re comparing packages. Same brand family, different formulation, different setting.
Outside these designated items, everything classified as a drug — prescription or OTC — is pharmacy territory.
What each tier may claim
The claim rules follow the tier, and this is where the practical difference lands.
| Category | Where to buy | May claim disease treatment or prevention? |
| Prescription drug | Pharmacy, with prescription | Yes |
| OTC drug | Pharmacy only | Yes |
| Quasi-drug | Pharmacy, retail, convenience store, online | Limited — minor or indirect effects |
| Health functional food | Pharmacy, mart, online, direct sales | No |
[Table 1] Categories, access and claims · Source: Summary of related systems[1][3]
The bottom row is the one to carry. As covered in the claims post, ingredients with disease treatment or prevention effects cannot be recognised as health functional food ingredients under Korean statute. A supplement claiming to prevent illness is making a claim its category doesn’t permit.
Quasi-drugs are approved by the MFDS and carry a 의약외품 designation on the package[1]. Businesses intending to import or sell them must obtain permission or file a notification with the MFDS beforehand[3], and the agency publishes its approval process for the category in English[4].
Why your usual product may be missing
Several ingredients sold freely as supplements elsewhere sit in the drug tiers here. Melatonin is the example that comes up most often for new arrivals — prescription-only in Korea.
And as covered in the ginkgo post, some ingredients exist in more than one tier simultaneously: available as a prescription or OTC medicine and as a supplement, under separate regulatory regimes with different approved wording.
That creates a duplication risk worth checking. Taking a prescribed product and a supplement containing the same ingredient means doubling a dose without noticing.
How to work out which tier you’re holding
Four checks, in order.
- Look for the designation on the package. 전문의약품, 일반의약품, 의약외품, or 건강기능식품 with its mark. One of these will be printed.
- Note where you found it. If it’s in a mart or online, it isn’t an OTC drug. If it’s behind the pharmacy counter, it may be prescription-only.
- Read what it claims. Disease treatment or prevention language belongs to the drug tiers. If a product with the health functional food mark makes that claim, the claim is outside its category.
- Ask a pharmacist if you’re unsure. They can tell you which tier a product sits in and whether the ingredient exists in another tier too.
And the point that runs through this series: the tier tells you what oversight the product received and what it may claim. It doesn’t tell you whether you need it.
Closing
What I’d underestimated was how much the category determines rather than describes.
It sets where a product can be sold, whether it can be shipped to your door, what it may say on the box, and what review it went through before reaching a shelf. Two products with similar contents can differ on every one of those depending on which tier they were approved into.
The quasi-drug tier explains a lot of what looks arbitrary — why a fatigue tonic sits by a convenience store till while a similar-looking product requires a pharmacist.
And the vitamin case is the one worth remembering. A nutrient product classified as an OTC drug isn’t available online at all, which means the thing you couldn’t find might not be unavailable. It might just be in a different building.
At a Glance
- Four categories: prescription drug, OTC drug, quasi-drug, health functional food
- Quasi-drugs have minor or indirect effects on the body and are sold in ordinary retail, convenience stores and online
- OTC drugs are pharmacy-only — no prescription, but not sold online or in marts
- Some vitamin and mineral products are classified as OTC drugs, making them pharmacy-only
- Only the drug tiers may claim disease treatment or prevention
- Health functional foods may never carry disease claims under Korean statute
- Convenience stores carry a fixed designated list (안전상비의약품), and those versions differ slightly in ingredients and dosage from pharmacy equivalents
- Some ingredients exist in more than one tier at once — a duplication risk worth checking
※ This article describes a regulatory framework for general information only. It does not evaluate any specific product and does not replace medical advice. Classification and designated lists are revised periodically — confirm current details with official sources. If you take prescription medication, check with a pharmacist before adding any supplement or OTC product, particularly where the same ingredient may appear in more than one product you’re taking.
References
- 하이닥, 「건강기능식품 vs 일반의약품 vs 전문의약품, 어떻게 다를까?」 (category definitions, quasi-drug scope, OTC-classified nutrient products, convenience store formulation differences), https://news.hidoc.co.kr/news/articleView.html?idxno=45547
- 「안전상비의약품 약국 외 판매의 의의와 과제」, Journal of the Korean Medical Association 55(9) (designated list management), https://synapse.koreamed.org/upload/synapsedata/pdfdata/0119jkma/jkma-55-843.pdf
- ChemLinked, “South Korea Quasi-Drug Regulation” (Pharmaceutical Affairs Act definition of 의약외품; MFDS permission requirement), https://cosmetic.chemlinked.com/cosmepedia/south-korea-quasi-drug-regulation
- Ministry of Food and Drug Safety, “Approval Process — Quasi-Drugs”, https://www.mfds.go.kr/eng/wpge/m_25/de011015l001.do