Citronella Essential Oil Science
As a concentrated form of antioxidants and phytochemicals taken from the plant’s stems and leaves, citronella oil has been used for centuries in China, Indonesia and Sri Lanka to help decrease rashes, inflammation — the root of most diseases — infections, pain and other health conditions.
Citronella oil comes from the Asian grass plant known as Cymbopogon nardus. It’s most commonly used as a natural fragrant oil, in insect repellents, as well as in beauty, household and perfume products.
According to dozens of clinical studies, pure citronella oil is an antiseptic, antimicrobial and antifungal treatment. The most popular use for citronella is as a constituent in homemade or commercially sold insect repellents, since it naturally repels mosquitos and other bugs. The U.S. Environmental Protection Agency considers citronella to be a “biopesticide” that has a nontoxic mode of action against insects.
Because it fights infections, bacteria and fungi, historically it’s also been used to sanitize surfaces and treat bites or parasites.
Benefits of Citronella Oil
According to various studies investigating the effects of these compounds, citronella oil has been shown to have the following benefits:
- Naturally repels insects
- Fights free radical damage
- Fights bacteria and fungi
- Reduces inflammation
- Promotes relaxation
- Fights respiratory infections
- Supports digestive/intestinal health
- Relieves muscle pain
- Helps control pets’ behavior
Today, there are more than 30 species of Cymbopogon grown wildly throughout parts of the world and used in Southeast Asian cooking and teas. There are two primary types of citronella used to create pure citronella oil: the Java type and the Ceylon type. Both originally come from parts of Asia, especially grassy areas of Sri Lanka. In terms of smell, benefits and uses, citronella oil is related to lemongrass essential oil and some other citrus oils.
Ceylon citronella is obtained from the Cymbopogon nardus Rendle plant and has the following active ingredients: geraniol (18 percent to 20 percent), limonene (9 percent to 11 percent), methyl isoeugenol (7 percent to 11 percent), citronellol (6 percent to 8 percent) and citronellal (5 percent to 15 percent). It has a scent similar to citrus fruits, wood and cinnamon.
The Java type is similar and derived from a related species calledCymbopogon winterianus Jowitt. Java citronella’s active ingredients include: citronellal (32 percent to 45 percent), geraniol (11 percent to 13 percent), geranyl acetate (3 percent to 8 percent) and limonene (1 percent to 4 percent). Of the two types, Java is thought to be more powerful, and therefore it’s usually more expensive. It has a darker color and “fresher” scent similar to lemon and lemon essential oil. Of citronella’s active ingredients, the three that are most researched and valued include citronellol, citronellal and geraniol.
Both types of citronella oil have widespread uses, including stress reduction, antibacterial or antiseptic action, and skin rejuvenation. Citronella essential oil is one of the most common aromatherapy oils and is part of what gives many household sprays and candles their signature scent. Additionally it can be used as a food additive for flavor and preservation, so you can sometimes find it in drinks, dairy products and desserts.
11 Citronella Oil Uses
- All-Natural Insect Repellent
Citronella has been registered as a gentle, plant-based insect repellent in the United States since 1948. It has even been shown to repel dangerousAedes aegypti mosquitoes, which are capable of spreading “dengue fever.” It’s also effective for helping to prevent body lice, head lice and flies.
According to some research, you need to reapply citronella oil about every 30–60 minutes for its bug-repelling effects to last. You can combine several drops with coconut oil and spread it on your body like lotion, or add some to a spray bottle with water and cover your skin, hair and clothes. Applying pure citronella oil directly to the body is considered more effective for fighting bugs than citronella candles are.
- Anti-Inflammatory and Pain Reducer
Due to its antioxidant properties and ability to increase blood flow, citronella is used as a natural arthritis treatment, specifically linked with reduced pain associated with orthopaedic problems like osteoarthritis and rheumatoid arthritis. Combine several (two to three) drops with a carrier oil like coconut oil and massage it into swollen joints, tissue and muscles, or soak in a warm bath of citronella oil to reduce swelling and pain.
- Relaxant and Stress Reducer
Commonly used to control emotions in aromatherapy, it can help relax your mind and contribute to reduced stress reactions and better sleep for people who can’t sleep. Try diffusing citronella oil in your home, massaging it into skin or spraying it onto your bed sheets.
- Digestive Aid
Citronella helps support the digestive organs by reducing inflammation and helping with detoxification and cleansing of the liver, stomach and gut. Certain compounds prevent the growth of bacteria in the digestive tract and can speed up healing of illnesses and wounds. It’s also capable of killing organisms (parasites or worms) within the small and large intestines.
For protection against leaky gut syndrome and autoimmune disease, infections of the colon, urethra, bladder, gastrointestinal tract, prostate, and kidneys, very small doses of citronella oil can be ingested (see more safety information on uses below).
- Detoxification Enhancer
As a type of natural diaphoretic and diuretic agent, citronella can increase sweating and urination that draws toxins out of the body. Drinking a combination of one to two pure citronella essential oil drops, raw honey andlemon with hot water can improve elimination of excess fats, sodium, uric acid and toxins.
- Natural Perfume or Room Spray
Because it has a clean, fresh scent similar to lemon or lemongrass, citronella is a common ingredient in soaps, candles, incense, perfumes and cosmetics. You can deodorize the scents in your home, dishwasher, refrigerator and laundry machine by diffusing citronella or running a very small amount through a cycle of your household appliances.
- Muscle Relaxant
When it comes to dealing with cramps, swelling and pain, citronella can help improve blood flow that lowers muscle spasms and tenderness. Try massaging citronella oil mixed with a carrier into sore muscles or onto the abdomen when dealing with PMS cramps.
- Kitchen Cleaner
Proven to have strong antifungal and antibacterial properties, citronella can help clean kitchen, bathroom or household surfaces without the need for harsh chemicals. Because of its compounds, including methyl isoeugenol, it’s effective for reducing food-born pathogens and even dangerous bacteria.
- Natural Skin Care Remedy
Aside from keeping away bug bites, research shows citronella can also helpheal dermatitis, naturally treat eczema, slow skin aging, heal bug bite scars and treat some fungal infections on the skin. It enhances penetration of skin and speeds up wound healing, which might be beneficial for remedying acne, getting rid of warts, treating boils and healing age spots.
It can also help skin appear youthful and smoother and even block damage done from sun exposure. Add a very small amount to coconut oil and massage it into the face, or try adding one to two drops to your shower or facial wash. As an easy-to-make home remedy for acne, try dabbing one drop of pure citronella essential oil on blemishes three times a day, but make sure you use a sterile cotton swab.
- Pet Controller
Although it might sound strange, citronella oil is effective in calming barking dogs and can even be used on furniture to help keep your pets off. As a bonus, when you spray citronella on your furniture or linens, it keeps them free from bacteria, pests and odors. Add several drops to a spray bottle along with water, shake it up, and spray it throughout your home and on household items.
- Natural Shampoo and Conditioner
One of the most popular uses for citronella oil is cleansing and conditioning the hair and scalp. It can help eliminate excess oil and greasiness of hair while also fighting dandruff and adding shine. Many people find it adds volume to hair, detangles knots and helps protect hair color from sun damage.
Add several drops to your shampoo or conditioner, or try making your own homemade recipe using a cleansing oil like coconut oil, which also benefits hair.
Citronella Oil Research and Studies
The active ingredients in citronella oil proven to have skin-saving, stress-fighting, bacteria-fighting properties include: citronellol, geraniol, linalol (linalool), citronellyl formate, citral, myrtenol, terpineol and methone. A long list of studies have shown positive effects of either some of these individual components or several used in combination together.
Like many citrus essential oils, citronella contains compounds that fight free radical damage and help reverse oxidative stress. A 2000 review published in the Journal of Agricultural Food Chemistry studied 34 different citrus essential oils and their components for radical-scavenging activities. They found that many citrus volatile components, including the main type found in citronella called geraniol, had high antioxidant capabilities for lowering inflammation and cellular damage.
Research shows that citronella’s geraniol also has strong antihelminthic activity, which means it effectively expels parasitic worms, bugs and leechesfrom the body by either stunning or killing them without causing any damage to the host. This is precisely the reason that citronella is used to prevent both internal and external infections and illnesses.
In studies regarding the effects of psycho-aromatherapy using citronella, citronella has been shown to help people enter relaxed moods with better control over negative emotions. When inhaled, citronella gives the pleasure of relaxation, invigoration and pleasant memories. It can serve as a natural and safe temporary remedy for anxiety, stress, trouble sleeping and depression.
Research shows that certain active ingredients in citronella are even effective for lowering stress reactions and pain in pregnant women. A 2014 clinical trial study conducted by Iran University of Medical Sciences found that anxiety scores were significantly lower in pregnant women after undergoing a 10-minute inhalation and foot bath with rose essential oil that contains many of citronella’s same active ingredients.
During pregnancy, labor and childbirth, anxiety, fear, stress, and pain are elevated; however, active ingredients in citronella — including geraniol, nerol, linalool and phenyl ethyl alcohol — can lower anxiety by up to 70 percent according to the research results.