Camphor

• Overview
• Uses
• Side Effects
• Precautions
• Interactions
• Dosing

Camphor used to be made by distilling the bark and wood of the camphor tree. Today, camphor is usually manufactured from turpentine oil. It is used in products such as Vicks VapoRub.

Camphor products can be rubbed on the skin (topical application) or inhaled. Be sure to read the label to find out how the product should be administered.

People apply camphor to the skin to relieve pain and reduce itching. It has also been used to treat toenail fungus, warts, insect bites, cold sores, hemorrhoids, and osteoarthritis.

Camphor is applied to the skin to increase local blood flow and as a "counterirritant," which reduces pain and swelling by causing irritation. Some people apply camphor to the skin to treat diseases of the airway and to treat heart symptoms. Camphor is also applied as an eardrop and for treating minor burns.

It is important not to apply camphor to broken skin, because it can enter the body quickly and reach concentrations that are high enough to cause poisoning.

Some people inhale camphor to reduce the urge to cough.

Although it is an UNSAFE practice, some people take camphor by mouth to help them cough up phlegm, for treating infections of the airway, for treating low blood pressure that occurs when standing up, and for intestinal gas (flatulence). Experts warn against doing this because, when ingested, camphor can cause serious side effects, even death.

Camphor is a well-established folk remedy, and is commonly used. Camphorated oil (20% camphor in cottonseed oil) was removed from the U.S. market in the 1980s because of safety concerns associated with accidental intake by mouth. It continues to be available without a prescription in Canada.

How does it work?

Camphor seems to stimulate nerve endings that relieve symptoms such as pain and itching when applied to the skin. Camphor is also active against fungi that cause infections in the toenails. In the nose, camphor seems to create a cold sensation so that breathing feels easier.

Likely Effective for...

• Cough. Camphor is FDA-approved as a chest rub in concentrations less than 11%.
• Pain. Camphor is FDA-approved for use on the skin as a painkiller in concentrations of 3% to 11%. It is used in many rub-on products to reduce pain related to cold sores, insect stings and bites, minor burns, and hemorrhoids.
• Skin itching or irritation. Camphor is FDA-approved for use on the skin to help itching or irritation in concentrations of 3% to 11%.

Possibly Effective for...

• Osteoarthritis. A rub-on cream containing camphor, glucosamine sulfate, and chondroitin sulfate seems to reduce the severity of symptoms of osteoarthritis by about half. Researchers believe it is probably the camphor, not the other ingredients, that relieves the symptoms.

Insufficient Evidence to Rate Effectiveness for...

• Insect bite. Early research shows that applying camphor along with menthol and eucalyptus oil might help reduce the size of mosquito bites.
• Toenail fungus (onychomycosis). . Early research shows that applying camphor along with lemon eucalyptus oil and menthol to the toenail area might help treat toenail fungus. Also, applying chest rub products containing camphor (such as Vicks VapoRub) to affected toenails daily until the infected nail grows out appears to clear fungal nail infections in some people.
• Low blood pressure after standing up. Early research suggests that taking a product containing camphor and hawthorn by mouth helps prevent drops in blood pressure upon standing. However, it is not clear if taking camphor alone provides the same benefits. Also, this product is not available in the US.
• Warts.
• Hemorrhoids.
• Other conditions.

More evidence is needed to rate the effectiveness of camphor for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

Camphor is LIKELY SAFE for most adults when applied to the skin in a cream or lotion in low concentrations. Camphor can cause some minor side effects such as skin redness and irritation. Do not use undiluted camphor products or products containing more than 11% camphor. These can be irritating and unsafe. Camphor is also LIKELY SAFE for most adults when inhaled as vapor in small amounts as a part of aromatherapy. Don't use more than 1 tablespoon camphor solution per quart of water.

Do not heat camphor-containing products (Vicks VapoRub, BenGay, Heet, many others) in the microwave. The product can explode and cause severe burns.

Camphor-containing products are LIKELY UNSAFE when applied to broken or injured skin. Camphor is easily absorbed through broken skin and can reach toxic levels in the body.

Camphor is UNSAFE when taken by mouth by adults. Ingesting camphor can cause severe side effects, including death. The first symptoms of camphor toxicity occur quickly (within 5 to 90 minutes), and can include burning of the mouth and throat, nausea, and vomiting. Other symptoms affect the nervous system, such as seizures, confusion, and muscular contractions, as well as effects on vision.

Pregnancy and breast-feeding: Taking camphor by mouth is UNSAFE during pregnancy or breast-feeding. The safety of applying camphor to the skin during pregnancy or breast-feeding is unknown. Don't risk your health or your baby's health. Avoid using camphor during pregnancy.

Children: Camphor is POSSIBLY UNSAFE in children when applied to the skin. Children tend to be more sensitive to the side effects. Doctors recommend that camphor products are not used on the skin in children. Camphor is UNSAFE in children when taken by mouth. Seizures and death can occur if these products are eaten. To be on the safe side, keep camphor-containing products away from children.

Liver disease: Taking camphor by mouth or applying it to the skin have been linked to potential liver damage. In theory, using camphor might make liver disease worse.

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Medications that can harm the liver (Hepatotoxic drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Using camphor might harm the liver. Applying camphor to the skin while taking medications that might also harm the liver can increase the risk of liver damage. Do not use camphor if you are taking a medication that can harm the liver.

Some medications that can harm the liver include acarbose (Precose, Prandase), amiodarone (Cordarone), atorvastatin (Lipitor), azathioprine (Imuran), carbamazepine (Tegretol), cerivastatin (Baycol), diclofenac (Voltaren), felbamate (Felbatol), fenofibrate (Tricor), fluvastatin (Lescol), gemfibrozil (Lopid), isoniazid, itraconazole, (Sporanox), ketoconazole (Nizoral), leflunomide (Arava), lovastatin (Mevacor), methotrexate (Rheumatrex), nevirapine (Viramune), niacin, nitrofurantoin (Macrodantin), pioglitazone (Actos), pravastatin (Pravachol), pyrazinamide, rifampin (Rifadin), ritonavir (Norvir), rosiglitazone (Avandia), simvastatin (Zocor), tacrine (Cognex), tamoxifen, terbinafine (Lamisil), valproic acid, and zileuton (Zyflo).

The following doses have been studied in scientific research:

APPLIED TO THE SKIN:

• For cough: A thick layer of 4.7% to 5.3% camphor ointment is applied to the throat and chest. The area may be covered with a warm, dry cloth or left uncovered.
• For skin itching: A 3% to 11% ointment is typically used three to four times daily.
• For pain: A 3% to 11% ointment is typically used three to four times daily.
• For osteoarthritis: A topical cream containing camphor (32 mg/gram), glucosamine sulfate (30 mg/gram), and chondroitin sulfate (50 mg/gram) as needed on sore joints for up to 8 weeks.