Limonene is the second-most common terpene found in cannabis strains

It is also commonly found throughout the plant kingdom, mainly in citrus fruits, and coniferous and broadleaved trees. Limonene is sometimes distinguished as “D-Limonene,” to differentiate it from “L-Limonene,” which has a pine scent as opposed to a citrus scent. The many natural sources of the terpene limonene include:

• Lemons – its namesake
• Limes
• Oranges
• Grapefruits
• Tangerines
• Maple trees
• Spruce trees
• Douglas fir trees – popular Christmas decoration
• Rosemary
• Juniper
• Peppermint

Flavor and aroma:

No surprise here: Limonene has a sharp, tangy aroma and sour flavor reminiscent of citrus fruit. Since it’s used as a citrus flavor in beverages, candy, and all kinds of foods, limonene will be easily recognizable to anyone.

What it does:

Limonene is said to improve mood and relieve stress. It is also said to help with mental focus, concentration, and clarity. However, there doesn’t seem to be pronounced recognition of limonene in contributing to entourage effects. Limonene is also being researched as a cancer treatment after findings that it may inhibit tumor growth, and has also been indicated in having anti-fungal properties. While limonene may prove out to have medical and therapeutic effects, even the cannabis strains with the most limonene have amounts too small to make a difference.

In other uses, limonene appears in many household products from cosmetics and body care products to perfumes and flavorings. It’s used in a wide variety of foods and beverages, in anything with a citrus taste. It also appears in herbicides, pesticides, solvents, cleaning products, hand soaps, air fresheners, and many other industrial fields. Notably, everything you’ve ever inhaled in your life that had a “fresh lemony scent” had limonene in it.

Where to find it:

• O.G. Kush
• Sour Diesel
• Super Lemon Haze
• Durban Poison
• Jack Herer
• Jack the Ripper
• Hindu Kush
• Dirty Girl
• Lemon G

In short, all strains with “sour” or “lemon” in the name usually have limonene.

Toxic advisory:

Limonene is toxic to aquatic life. In other words, do not introduce it into your aquarium.

Limonene concentrated on the skin can produce irritation from contact dermatitis, but otherwise does not have any apparent serious health effects.

Limonene is flammable. If you buy a bottle of it for a vape oil additive, keep the bottle away from open flames.

Fun facts:

While limonene has no known toxic effects on household pets and even appears as an ingredient in pet shampoo for its insect-repelling properties, cats and dogs have shown a noted dislike for strong citrus smells in general, limonene no exception.

Limonene is venturing into “quack” territory with the exaggerated health benefit claims. For instance, this source claims that limonene boosts immunity, improves gallbladder conditions, relieves indigestion, prevents cancer, prevents insulin resistance, kills pathogens, aids in weight loss, and decreases insomnia. None of the health studies we can find prove anything conclusively yet.

Citrus fruits in general do have a number of widely-supported health benefits, but this has to do with other components and limonene is not mentioned.