A Guide to Using Essential Oils Internally

What you need to know before using essential oils internally?

Essential oils have long been cherished for their therapeutic benefits, from enhancing relaxation and improving sleep to soothing sore muscles and supporting overall wellness. While most people are familiar with the external use of essential oils—like diffusing them for aromatherapy or applying them topically when diluted—there’s a growing interest in using essential oils internally.

When done correctly, ingesting essential oils can offer a range of potential benefits, from supporting digestion to promoting immune health. However, this method comes with its own set of risks and precautions. Not all essential oils are safe for internal use, and proper guidance is essential to avoid adverse reactions.

In this article, we’ll explore the key considerations and best practices for using essential oils internally, helping you make informed choices about which oils are safe, how to consume them, and when to seek professional advice. Whether you’re new to essential oils or looking to expand your knowledge, understanding the right approach to internal use is crucial for maximizing their benefits safely.

Warning, safety cautions

Essential oils are not intended to diagnose, treat, or prevent any disease, nor do they replace medications or therapies prescribed by a physician. They are not medicinal products and do not qualify as drugs. Based on experience, essential oils may have complementary therapeutic effects. If you are unsure about how an essential oil might affect you or your child, consult your general practitioner and/or a qualified aromatherapist. Before using any new essential oil (especially internally or directly on the skin), perform a patch test.

Understanding the internal use of essential oils

Internal use involves consuming essential oils by adding them to food, beverages, or taking them in capsules. While some essential oils are recognized as safe for ingestion, not all are suitable for this purpose. The U.S. Food and Drug Administration (FDA) has a list of essential oils generally recognized as safe (GRAS) for consumption, primarily as flavoring agents. However, this designation doesn’t imply unlimited use or guarantee safety in large quantities.

Safety guidelines for internal use of essential oils

Dilution

Always dilute essential oils before ingestion. Mix them with a carrier oil, such as olive or coconut oil, or incorporate them into food or beverages to reduce the risk of irritation or adverse reactions.

Reactions

If you experience nausea, dizziness, stomach pain, or any unusual symptoms after ingesting an essential oil, discontinue use immediately and seek medical attention. These may be signs of toxicity or an allergic reaction.

Key takeaway

Many oils with high levels of phenols, ketones, or other compounds can quickly become toxic when taken internally, especially without dilution or professional oversight. These are generally avoided for ingestion.

Warning, safety cautions

Essential oils are not intended to diagnose, treat, or prevent any disease, nor do they replace medications or therapies prescribed by a physician. They are not medicinal products and do not qualify as drugs. Based on experience, essential oils may have complementary therapeutic effects. If you are unsure about how an essential oil might affect you or your child, consult your general practitioner and/or a qualified aromatherapist. Before using any new essential oil (especially internally or directly on the skin), perform a patch test.

Essential Oils Generally Regarded as Hazardous or Toxic for Internal Use

Many essential oils contain potent constituents (e.g., phenols, ketones, methyl salicylates, thujone, safrole) that can lead to toxicity, liver damage, nervous system issues, or other dangerous side effects when taken internally—or in some cases, even externally at high concentrations. Some of the more notable “avoid” or “extreme caution” oils are:

Wintergreen (Gaultheria procumbens)

Main Constituent: Methyl salicylate (90%+).
Toxicity: High risk of salicylate toxicity (similar to aspirin overdose) if misused or ingested.

Pennyroyal (Mentha pulegium)

Main Constituent: Pulegone.
Toxicity: Known hepatotoxic (liver damaging) and neurotoxic properties. Documented fatalities from ingestion.

Wormwood (Artemisia absinthium)

Main Constituent: Thujone.
Toxicity: Neurotoxic effects, seizures in high doses. Historically used in absinthe, but that usage is highly regulated and modern absinthe is thujone-reduced.

Rue (Ruta graveolens)

Main Toxic Component: Various alkaloids and volatile compounds.
Toxicity: Highly irritating, can cause severe gastrointestinal issues, organ damage.

Sassafras (Sassafras albidum)

Main Toxic Compound: Safrole.
Toxicity: Potentially carcinogenic, banned as a food additive in the U.S.

Birch (Betula lenta)

Main Constituent: Methyl salicylate (similar to wintergreen).
Toxicity: High risk of salicylate overdose if ingested.

Camphor (Cinnamomum camphora)

Main Constituent: Camphor.
Toxicity: Neurotoxic (convulsions, respiratory problems) in relatively small amounts if ingested.

Tansy (Tanacetum vulgare)

Main Constituent: Thujone.
Toxicity: Neurotoxic, potential for seizures and liver damage.

Thuja (Thuja occidentalis)

Main Toxic Compound: Thujone.
Toxicity: Neurotoxic, potential for seizures and organ toxicity.

Yellow Star Anise (Illicium verum var. anisatum) [Japanese Star Anise]

Toxic Constituents: Neurotoxic compounds, not to be confused with Chinese star anise (Illicium verum).
Toxicity: Neurotoxic, can cause severe issues if ingested by mistake.

Tea Tree (Melaleuca alternifolia)

Main Constituents: Terpinen-4-ol, γ-terpinene, α-terpinene.
Toxicity: Commonly used topically; known to be toxic if swallowed (even moderate amounts).

Eucalyptus (Eucalyptus globulus and others)

Main Constituent: 1,8-cineole (Eucalyptol).
Toxicity: Can cause severe poisoning (nausea, vomiting, CNS depression) if ingested inappropriately or in large doses.

Oregano (Origanum vulgare) [In High Concentrations]

Main Constituents: Carvacrol, thymol.
Toxicity: Can irritate mucous membranes and digestive tract; must be heavily diluted and typically avoided for routine oral use unless under direct supervision.

Cinnamon Bark (Cinnamomum verum or C. zeylanicum)

Main Constituents: Cinnamaldehyde, eugenol.
Toxicity: Highly irritating to mucous membranes, potential liver toxicity if used in large amounts.

Important additions

Note that even an essential oil neither listed here as safe, nor as unsafe for taking internally, don’t use it automatically without collecting further information about it from its manufacturer. Always be informed about the very exact essential oil of yours and search for “food grade” or “safe for internal usage” labels and certifications. Not every manufacturer produces pure, safely to use other than aromatically essential oils. Always keep the labels for further referral.