Yes, melaleuca and tea tree refer to the same plant. The essential oil sold as “tea tree oil” comes from Melaleuca alternifolia, a species native to Australia. But “melaleuca” is also the name of a large plant genus containing close to 300 species, so the overlap between the two terms isn’t perfectly clean.
How Melaleuca and Tea Tree Are Connected
Melaleuca is the scientific genus name for a group of nearly 300 species in the myrtle family, almost all native to Australia. Melaleuca alternifolia is the specific species whose leaves produce the essential oil labeled “tea tree oil” on store shelves. So when someone says “melaleuca oil,” they nearly always mean the same product as “tea tree oil.”
The common name “tea tree” traces back to Captain James Cook, who brewed the leaves of related plants into a drink for his crew to prevent scurvy. The name stuck, even though the plant has nothing to do with the tea you’d steep in a mug (that comes from Camellia sinensis, a completely different family).
Other Melaleuca Species Are Not “Tea Tree”
Here’s where it gets slightly complicated. A few other melaleuca species, including M. linariifolia and M. dissitiflora, can produce oils with a similar chemical profile. Technically, those oils can meet the international standard for tea tree oil. In practice, though, virtually all commercial tea tree oil comes from M. alternifolia.
Other well-known melaleuca species serve entirely different purposes. Melaleuca quinquenervia, the broad-leaved paperbark tree found in eastern Australia and Papua New Guinea, is an ornamental and wetland species. In parts of Florida, it’s actually classified as an invasive plant. Its oil (sometimes called niaouli oil) has a different composition and is not sold as tea tree oil.
Melaleuca cajuputi produces cajuput oil, another distinct essential oil used in traditional medicine across Southeast Asia. So while every tea tree oil plant is a melaleuca, not every melaleuca is a tea tree.
What Makes Tea Tree Oil Distinct
The international standard (ISO 4730) defines exactly what qualifies as tea tree oil based on its chemical makeup. The key compound, terpinen-4-ol, must make up 35% to 48% of the oil. Meanwhile, a compound called 1,8-cineole (which can irritate skin at high concentrations) must stay below 10%. If an oil doesn’t hit those numbers, it can’t be marketed as tea tree oil regardless of which melaleuca species it came from.
Terpinen-4-ol is the compound responsible for most of tea tree oil’s antimicrobial activity. It works by dissolving into the membranes of bacteria and fungi, disrupting their structure, making them leak, and ultimately killing the cells. This gives tea tree oil broad-spectrum activity against a range of microorganisms.
The Melaleuca Company Adds to the Confusion
Some people searching this question are actually wondering about Melaleuca, Inc., a U.S.-based wellness company that sells household and personal care products. The company took its name from the melaleuca plant genus, and some of its products contain tea tree oil. But the company name and the plant are not interchangeable. Melaleuca, Inc. is a brand; Melaleuca alternifolia is a plant species. Products from the company may or may not contain tea tree oil depending on the specific item.
Common Uses of Tea Tree Oil
Tea tree oil’s antimicrobial properties make it a popular ingredient in skin care, particularly for acne. A clinical trial comparing 5% tea tree oil gel to 5% benzoyl peroxide lotion in 124 patients with mild to moderate acne found that both treatments reduced breakouts. The tea tree oil worked more slowly but caused fewer side effects like dryness and stinging.
You’ll also find tea tree oil in shampoos marketed for dandruff, in wound-care products, and in natural household cleaners. Concentrations in consumer products typically range from 1% to 10%, with 5% being the most studied for skin applications.
Freshness Matters for Safety
Tea tree oil can oxidize over time, and aged oil is more likely to cause skin irritation or allergic contact dermatitis. As the oil breaks down, its key components (including terpinen-4-ol and alpha-terpinene) degrade into compounds that are more reactive with skin proteins. If your bottle of tea tree oil is old, smells different than when you bought it, or has been stored in heat or sunlight, it’s best to replace it. Keeping tea tree oil in a cool, dark place with the cap tightly sealed slows this process.
Tea Tree Oil and Pets
One important distinction for pet owners: tea tree oil is toxic to dogs and cats, especially in concentrated form. A review of 443 cases of tea tree oil exposure in pets found that undiluted (100%) oil caused serious symptoms including excessive drooling, lethargy, muscle tremors, and difficulty walking. Signs appeared within 2 to 12 hours and lasted up to 3 days. Younger and smaller cats were at the highest risk of severe illness. Products formulated with very low concentrations of tea tree oil may appear in pet shampoos, but applying pure tea tree oil directly to a pet’s skin or fur is dangerous.