Limonene is one of hundreds of constituents found in essential oils. As an individual compound, or as part of a "whole" essential oil, it provides numerous health benefits which have helped bring attention to the therapeutic benefits of the oils themselves.

In this article, I'll cover some of those health benefits, as well as explain where to find limonene and how to determine how much you get if you use essential oils.

While essential oils provide a plethora of health benefits when used as a "whole" essential oil, it's sometimes easier to understand how the individual compounds affect our health. That's just how nutrition science and research works.

For example, we know that animal-based proteins like steak, bison, and whey are an important part of a healthy, high-protein diet, because researchers have studied the effects of the essential amino acids, creatine monohydrate, and other nutrients found in those foods. However, that doesn't mean you should only eat the amino acids and creatine. Animal protein contains many other compounds that enhance health, which is why you eat the whole food and supplement your diet with creatine, amino acids, omega-3s, and other micronutrient, botanicals, and ergogenic compounds.

It's the same thing with essential oils. While there could be some benefit to supplementing with limonene alone, there's also plenty of evidence to show why using the whole essential oil would be better. 

Read also: Essential Oils For Fitness: Research, Anecdotal Evidence, Experimentation.

With all that said, let's get to the topic of today's article: d-limonene.

What is d-Limonene?

Though it's found in another isomer form, r-limonene, the more prevalent and studied form is d-limonene. For readability, I simply use limonene in this article, with the understanding I'm referring to d-limonene.

d-limonene is one of the most common terpenes found in nature. But, what the heck is a terpene? A terpene a class of volatile compounds commonly made by coniferous trees and citrus fruits. Because of their volatility, they quickly dissipate when exposed to the air, which is why you don't find them in dried herbs. Terpenes have a strong odor designed to ward off pests in plants, and are used medicinally and supplementally. Limonene is one of those terpenes, and based on the name of it, you might (accurately) guess that it smells like somewhat like lemon.

Where Do You Get Limonene?

Though you’re not getting therapeutic doses, you’re probably consuming more limonene than you realize. It’s used as a fragrance and flavor in a number of foods, such as candy, gum, soft drinks, ice cream, and (hopefully you don’t drink it, but…) fruit juice.

Aside from food and dietary supplements, limonene is also used as a healthier cleaning substance in household products, manufacturing, and industrial printing, as a degreaser for metals, and in paint as a solvent. You'll also see limonene on the label of shampoos, soaps, fragrances, and other personal care products. 

The most abundant sources of limonene are the peels of citrus fruits (which is where the essential oils are derived), dill, caraway, fennel, celery, and turpentine, not that you should consume turpentine.

For commercial and industrial use,