Ketotifen eye drops are available over the counter in the United States. You can find them at most pharmacies and drugstores without a prescription, sold under brand names like Zaditor and Alaway. However, the oral tablet form of ketotifen is a different story and is not FDA-approved for sale in the US at all.
What You Can Buy Without a Prescription
The OTC version of ketotifen is specifically the ophthalmic solution, meaning eye drops. These contain ketotifen at a 0.025% concentration and are labeled as antihistamine eye drops for temporary relief of itchy eyes due to allergies. They were previously available only by prescription but have since switched to OTC status at the same strength.
Zaditor (now marketed under the Systane brand) and Alaway are the two most widely available OTC versions. Store-brand generics are also common and contain the same active ingredient at the same concentration. Prices vary, but generics tend to cost significantly less than the name brands.
What Ketotifen Eye Drops Treat
Ketotifen works in two ways. It blocks histamine receptors in the eye, which stops the immediate allergic itch. It also stabilizes mast cells, the immune cells that release histamine and other inflammatory chemicals in the first place. This dual action makes it more effective for ongoing allergy relief than eye drops that only do one or the other.
The standard dose is one drop in the affected eye twice a day, spaced 8 to 12 hours apart. It’s approved for adults and children 3 years and older. For children under 3, a doctor needs to determine whether it’s appropriate.
Side Effects and Practical Tips
Most people tolerate ketotifen eye drops well. The most commonly reported side effects are mild: temporary burning or stinging when you put the drops in, headache, dry eyes, and a runny nose. Less common effects include blurred vision, sensitivity to light, and eye discharge.
If you wear soft contact lenses, there’s an important detail to know. The drops contain a preservative called benzalkonium chloride, which soft lenses can absorb. Remove your contacts before applying the drops and wait at least 10 minutes before putting them back in. If your eyes are already red, you should skip the contacts entirely until the redness clears.
Oral Ketotifen Is Not Available OTC
This is where many people get confused. Oral ketotifen (tablets and liquid) is approved in countries like Japan, Canada, and across Europe for conditions including asthma and allergic disorders. In the UK, oral ketotifen requires a prescription. In the United States, the oral form has never been FDA-approved, so it is neither prescription nor OTC here. Some people obtain it through compounding pharmacies or international sources, but that’s a separate process that involves a prescriber.
If you’ve seen ketotifen discussed online for conditions like mast cell activation syndrome or chronic hives, those conversations are almost always about the oral form. The OTC eye drops won’t help with systemic allergic conditions since the medication stays local to the eye and doesn’t reach meaningful levels in the bloodstream.
Where to Find It
OTC ketotifen eye drops are stocked in the eye care aisle of most major pharmacies, grocery stores with pharmacy sections, and online retailers. You don’t need to ask a pharmacist to retrieve them from behind the counter. They’re shelved alongside other allergy eye drops like artificial tears and redness relievers. Look for “antihistamine eye drops” on the box, and check that the active ingredient lists ketotifen 0.025% to confirm you’re getting the right product.