Mexican Oregano vs. Oregano: Two Plant Families, One Shared Flavor

Mexican oregano and oregano don’t even come from the same plant family. Mexican oregano is the leaf of Lippia graveolens, a shrub in the verbena family (Verbenaceae); oregano is Origanum vulgare, a perennial in the mint family (Lamiaceae). They still taste alike because both oils are built on the same two phenols, thymol and carvacrol, in different proportions.¹² Mexican oregano is the stronger, sharper of the two, but in America’s Test Kitchen’s side-by-side tasting the difference in finished dishes was minimal.³

Side by side

The flavor row is how we’d describe them, and it lines up with the sources. PROSEA calls the Mexican herb stronger, sharper and more pungent than Origanum,¹ and ATK’s tasters found Mediterranean oregano milder and faintly sweeter, and the Mexican type stronger, with a hint of menthol.³

Why two unrelated plants share a name

“Oregano” names a flavor, not a genus. A 2020 review of oregano chemistry notes that the name goes on several Origanum species and on plants in other genera, Lippia among them.² What links them is the oil. Mexican oregano’s family tie is to lemon verbena, Aloysia citrodora, which Kew also places in Verbenaceae; oregano’s relatives are mint, thyme and marjoram.

The chemistry, sample by sample

Each figure belongs to the oil it was measured on. They’re essential-oil numbers from different studies, not dried leaf from a jar, so don’t merge them into one comparison.

On these figures, Mexican oregano leans on thymol and Mediterranean oregano usually leans on carvacrol. ATK notes that both plants contain carvacrol.³ A 2021 review of L. graveolens also names β-caryophyllene and p-cymene among its terpenes.⁷ We didn’t find any study that measured both herbs side by side under the same conditions.

The differences that change a dish

Strength

The Mexican herb is the stronger one, going by both PROSEA and ATK’s tasting.¹³ In a dish built around a teaspoon of dried oregano, that’s the difference you’re most likely to notice.

Which cooking it belongs to

Mexican oregano is an important spice in Mexico and Central America. US extension recipes use it in chile cooking. NMSU’s New Mexico red chile sauce adds crushed dried Mexican oregano near the end and simmers another 5–7 minutes,⁸ and a University of Tennessee white chicken chili calls for 2 teaspoons.⁹ It also goes into pozole, beans, salsas and adobos, often with cumin and dried chiles.

Oregano is the herb of Italian and Greek cooking. It’s essential in Italian pizza and pasta sauces, Greek salads and gyros, and a key ingredient in Mediterranean and Middle Eastern cooking.

Long cooking

Both are used dried, and dried oregano handles heat well. America’s Test Kitchen counts oregano among the hearty herbs that go in early,¹⁰ and in its dried-versus-fresh tests dried oregano held up reasonably well in dishes with more than 20 minutes of cooking and a good amount of liquid. In chili, tasters actually preferred dried oregano to fresh.¹¹ The University of Delaware’s general rule for long simmering is to add herbs during the last 45 minutes.¹² We found no test of how Mexican oregano holds up over long cooking.

Can one stand in for the other?

Yes, in most cooked dishes. ATK tried both kinds in tomato sauce and in mojo-marinated skirt steak and noticed only minimal differences.³ Maggie Unzueta of Mama Maggie’s Kitchen, writing about Mexican cooking, says most cooks of Mexican food use regular oregano all the time.¹³

• Oregano in place of Mexican oregano (Attributed). RawSpiceBar’s Joseph Rosenblatt says to start with 1.5 times as much regular oregano. Elsewhere the same article suggests about 25% more, so the merchant’s own advice runs from 1 1/4 to 1 1/2 times.¹⁴ Since ATK found only minimal differences,³ the cautious route is to start with an equal amount and add the rest after tasting. See Mexican oregano substitutes.
• Mexican oregano in place of oregano (Method). The Mexican herb is the stronger one,¹³ so start with about three quarters of the oregano amount and taste. Our oregano substitutes page uses the same starting point.
• Rub it first. Unzueta suggests rubbing dried oregano between your hands to release its flavor,¹³ and the University of Delaware suggests crushing dried herbs for the same reason.¹²

You’ll notice the swap most in a raw salsa or a quick dish where the herb doesn’t cook down.

What isn’t known

• You’ll often see Mexican oregano described as having a licorice note. None of the sources we reviewed mentions licorice; ATK’s tasters reported a hint of menthol instead.³
• We couldn’t trace the common claim that Mexican oregano is used as a tea herb to a source we could open.
• The claim that oregano most likely originated in Greece doesn’t match Kew, which gives a native range from Macaronesia to China.⁵

Related

• Profiles: Mexican oregano, oregano, lemon verbena, marjoram
• Substitutes: Mexican oregano substitutes, oregano substitutes
• Comparisons: marjoram vs. oregano, oregano vs. thyme, cilantro vs. oregano, fresh oregano vs. dried
• Best spices for chili and too much oregano?