Essential Oils and Phototoxicity

Essential oils have been treasured for centuries for their therapeutic and aromatic properties. They are widely used in aromatherapy, skincare, and even household products due to their soothing effects, antibacterial benefits, and natural fragrance. However, not all essential oils are completely risk-free. A lesser-known but significant concern when using certain oils, particularly citrus essential oils, is phototoxicity.

Phototoxicity occurs when certain substances, including some components in essential oils, react with ultraviolet (UV) light, causing adverse skin reactions such as burns, rashes, or hyperpigmentation. When applied topically and then exposed to sunlight or tanning beds, photosensitive essential oils can exaggerate the skin’s reaction to UV light.

In this blog, we’ll dive deep into phototoxicity, its causes, how to avoid it, and how to use phototoxic essential oils safely.

What Is Phototoxicity?

Phototoxicity refers to a skin reaction that happens when a phototoxic chemical reacts with UV radiation. This reaction can cause symptoms such as redness, burns, blisters, or discoloration. In severe cases, the skin may develop long-term sensitivity or dark spots.

When it comes to essential oils, phototoxicity primarily occurs when compounds within the oils react with sunlight. Most of these reactive compounds are found in citrus essential oils due to their high content of chemical components like furanocoumarins.

Common Symptoms of Phototoxic Reactions

• Redness or irritation
• Burning sensation
• Blisters or rashes
• Skin discoloration (hyperpigmentation)
• Increased skin sensitivity to light

Photosensitivity and Citrus Essential Oils

Among the wide array of essential oils, citrus oils stand out for their refreshing, uplifting aromas and numerous therapeutic benefits. However, these oils are also known for their potential to cause photosensitivity, a heightened skin reaction when exposed to ultraviolet (UV) light. This reaction occurs because certain citrus oils contain natural chemical compounds that can exaggerate the skin’s response to sunlight, potentially leading to adverse effects such as irritation, redness, burns, or long-term pigmentation issues.

Why Are Citrus Essential Oils Phototoxic?

The main culprits behind this reaction are compounds called furanocoumarins, particularly bergapten and psoralens. These chemicals, when activated by UV light, can cause cell damage and inflammation in the skin. Once these compounds penetrate the skin and interact with UV radiation, they can generate free radicals that harm skin cells, leading to visible signs like redness, burning, blistering, or hyperpigmentation.

Citrus oils are particularly prone to this reaction because their chemical composition naturally contains these light-reactive compounds, especially when extracted through cold pressing—a method that preserves the full spectrum of plant chemicals.

Citrus Essential Oils Most Commonly Associated with Phototoxicity

Certain citrus essential oils are more likely to cause photosensitive reactions, especially when used topically and followed by sun exposure. Here are the main citrus oils known for their phototoxic risks:

Bergamot Oil (Citrus bergamia)

Known for its delightful, citrusy-floral aroma, bergamot oil contains high levels of bergapten, one of the most potent phototoxic agents found in essential oils. This makes it particularly risky when applied to the skin before sun exposure. Despite this, bergamot remains a favorite in perfumes and aromatherapy for its mood-lifting properties—though it's safest when used in products that have undergone bergapten removal.

Lemon Oil (Citrus limon)

While lemon essential oil offers a bright, refreshing scent and is known for its cleansing and mood-enhancing properties, it can cause skin sensitivity when cold-pressed. The phototoxic compounds in lemon oil can trigger skin irritation if the treated skin is exposed to sunlight. However, steam-distilled lemon oil typically lacks these phototoxic components, making it a safer option for topical use.

Lime Oil (Citrus aurantifolia)

Similar to lemon, lime oil can be phototoxic, particularly when expressed rather than distilled. Expressed lime oil retains its furanocoumarins, increasing the likelihood of photosensitive reactions upon UV exposure. Despite this, lime oil is prized in aromatherapy for its energizing and uplifting qualities.

Grapefruit Oil (Citrus paradisi)

Derived from the peel of the grapefruit, this oil is loved for its fresh, citrusy scent and metabolism-boosting effects in aromatherapy. However, it contains notable amounts of furanocoumarins, which can cause phototoxic reactions if applied to the skin and followed by sun exposure.

Phototoxic Essential Oils to Watch Out For

Here is a list of phototoxic essential oils that should be used cautiously if you plan to be exposed to sunlight:

Essential Oils That Are NOT Phototoxic

Not all essential oils carry the risk of phototoxicity. Here are some safe alternatives for sun-loving individuals:

How Does Phototoxicity Occur?

When applying phototoxic essential oils topically, UV light exposure activates the phototoxic compounds within the oil. This reaction generates free radicals that damage skin cells, leading to inflammation, irritation, and potential pigmentation issues.

Factors That Increase the Risk of Phototoxic Reactions:

• Direct exposure to UV light shortly after application.
• Using undiluted essential oils on the skin.
• High concentrations of phototoxic oils in skincare products.
• Having photosensitive skin or pre-existing skin conditions.

Avoiding Phototoxicity: Essential Oil Safety Tips

To enjoy the benefits of essential oils without the risks of phototoxicity, it’s essential to follow proper usage guidelines.

Dilution in a Carrier Oil

One of the most effective ways to prevent phototoxic reactions is by diluting essential oils with a carrier oil (like jojoba oil or sweet almond oil). For phototoxic oils, a dilution rate of 0.5-1% is recommended to minimize adverse reactions.

Avoid Sun Exposure After Application

If you’ve applied a phototoxic oil, avoid sun exposure for at least 12-24 hours. This includes avoiding tanning beds and direct sunlight.

Use Steam-Distilled Citrus Oils

Unlike cold-pressed oils, steam-distilled citrus oils usually do not contain phototoxic compounds. For example, distilled lemon essential oil offers the same refreshing scent without the risk of phototoxicity.

Conduct Patch Tests

Before using any essential oil topically, conduct a patch test on a small area of your skin to ensure you don’t experience irritation or allergic reactions.

Be Mindful of Product Labels

Some skincare products contain citrus essential oils without mentioning their phototoxic potential. Always check ingredient lists for any phototoxic compounds.

Phototoxicity From Other Sources: Sunscreens and Drugs

Phototoxicity doesn’t only stem from essential oils. Certain medications and skincare products, including some sunscreens, can also increase photosensitivity.

Phototoxicity from Sunscreens

While it might seem counterintuitive, some sunscreens contain ingredients that can increase sun sensitivity. Always choose broad-spectrum sunscreens and check labels for potentially phototoxic compounds.

Phototoxicity from Drugs

Certain medications can also increase the skin’s sensitivity to UV light, including:

• Antibiotics (e.g., tetracyclines)
• Non-steroidal anti-inflammatory drugs (NSAIDs)
• Antihistamines
• Diuretics

If you're taking medications, consult your healthcare provider before using essential oils known for their phototoxic properties.

DIY Recipes Using Non-Phototoxic Essential Oils

If you’re worried about phototoxic reactions, here are a few DIY essential oil blends that are safe for daytime use:

1. Refreshing Facial Mist

• 100 ml distilled water
• 5 drops lavender essential oil
• 5 drops peppermint essential oil
• 1 tablespoon aloe vera gel

2. Relaxing Body Oil

• 100 ml jojoba oil
• 10 drops chamomile essential oil
• 5 drops frankincense essential oil

3. Energizing Diffuser Blend

• 4 drops peppermint oil
• 4 drops rosemary oil
• 2 drops lemon oil (steam-distilled to avoid phototoxicity)

Conclusion

Citrus essential oils are renowned for their refreshing scent and therapeutic benefits, derived from the natural compounds found in citrus fruit. These oils are widely used in aromatherapy, skincare, and natural remedies. However, while essential oils contain molecules with healing properties, some citrus essential oils are phototoxic and can cause adverse skin reactions when exposed to sunlight.

When oils are applied topically and then exposed to UV light, they can trigger skin irritation, redness, or even blistering. This reaction is due to natural chemicals, such as furanocoumarins, found in many citrus oils like lemon juice, tangerine, grapefruit, and bergamot. These compounds can exaggerate the skin's sensitivity to UV radiation, causing phototoxicity. In contrast, distilled citrus fruit oils often eliminate these reactive elements, meaning the oil is not phototoxic and safer for topical use.

To minimize risk, it’s essential to understand which oils are phototoxic and how to use them safely. Choosing distilled citrus oils or properly diluting expressed oils in a carrier oil can significantly reduce the chance of skin reactions. It’s also wise to avoid sun exposure for 12–24 hours after applying phototoxic oils and to consult a health care professional if you have sensitive skin.

While photosensitive oils can pose risks, they also offer many benefits when used correctly. For those who love essential oils, understanding the difference between expressed citrus oils and distilled citrus alternatives is crucial for safe application. Whether using oils like neroli or experimenting with blends, being aware of potential reactions allows you to enjoy the power of essential oils safely and effectively, without compromising skin health. Always stay protected from phototoxicity by using essential oils responsibly.