C Unclear or conflicting scientific evidence
- Aromatherapy : Aromatherapy refers to many different therapies that use essential oils. The oils are sprayed in the air, inhaled, or applied to the skin. Essential oils are usually mixed with a "carrier" oil, usually a vegetable oil or alcohol. Massage is often used to deliver oils into the body because it is considered the most effective method. A well-designed human study in patients with alopecia areata examined the effects of massaging a mixture of essential oils into the scalp daily for seven months. The mixture included oils of cedarwood, lavender, rosemary, and thyme in carrier oils of grapeseed and jojoba. A significant improvement was seen in photographs of the skin of patients using the mixture of oils compared to patients using carrier oils alone. Although these results are promising, further research is needed before a firm conclusion can be made.
- Essential oils should be administered in a carrier oil to avoid toxicity. Avoid with history of allergic dermatitis. Use cautiously if driving/operating heavy machinery. Avoid consuming essential oils. Avoid direct contact of undiluted oils with mucous membranes. Use cautiously if pregnant.
- Beta-sitosterol : Beta-sitosterol is found in plant-based foods, such as fruits, vegetables, soybeans, breads, peanuts, and peanut products. It is also found in bourbon and oils, such as olive oil, flaxseed, and tuna. Early research suggests that beta-sitosterol may help treat androgenetic alopecia. However, further research is needed to determine whether or not this treatment is safe and effective in humans. Avoid if allergic or hypersensitive to beta-sitosterol, beta-sitosterol glucoside, or pine. Use cautiously with asthma, breathing disorders, diabetes, primary biliary cirrhosis (destruction of the small bile duct in the liver), ileostomy, neurodegenerative disorders (such as Parkinson's disease or Alzheimer's disease), bulging of the colon, short bowel syndrome, celiac disease, or sitosterolemia. Use cautiously with a history of gallstones. Avoid if pregnant or breastfeeding.
- Cedar : Cedar is native to the mountains of the western Himalayan and the Mediterranean regions. In one clinical study, patients with alopecia areata who were massaged with a combination of cedarwood oil, other aromatic oils, and carrier oils had significantly improved symptoms.
- Avoid if allergic or hypersensitive to cedar, its pollen, wood dust, constituents, or members of the Pinaceae family. Avoid if pregnant or breastfeeding.
- Hypnosis, hypnotherapy : Hypnosis is a trance-like state in which a person becomes more aware and focused and is more open to suggestion. Hypnotherapy has been used to treat health conditions or to change behaviors. Based on early study, hypnosis may help improve psychological well-being and physiological outcome in patients with alopecia areata. In other words, hypnotherapy may help patients cope with the effects of their hair loss. Larger, well-designed studies are needed before a firm conclusion can be drawn.
- Use cautiously with mental illnesses, such as psychosis/schizophrenia, manic depression, multiple personality disorder, or dissociative disorders. Use cautiously with seizure disorders.
- Lavender : Lavender is grown around the world. Oils from the flowers are used in aromatherapy, baked goods, candles, cosmetics, detergents, jellies, massage oils, perfumes, powders, shampoo, soaps, and teas. Small studies have shown that patients who massage essential oils (thyme, rosemary, lavender, and cedarwood) into their scalps daily experienced an improvement in alopecia. More research of lavender alone is need before a firm conclusion can be made.
- Avoid if allergic or hypersensitive to lavender. Avoid with a history of seizures, bleeding disorders, eating disorders (anorexia, bulimia), or anemia (low levels of iron). Avoid if pregnant or breastfeeding.
- Onion : Onion juice applied topically was shown to increase hair regrowth in alopecia areata patients, especially women. More research is needed to confirm these results. Avoid if allergic or hypersensitive to onion (Allium cepa), its constituents, or members of the Lilaceae family. Use cautiously with hematologic (blood) disorders, diabetes, hypoglycemia (low blood sugar), and hypotension (low blood pressure). Use cautiously if taking anticoagulants or antiplatelets (blood thinners). Avoid if pregnant or breastfeeding in medicinal doses.
- Para-aminobenzoic acid : Also known as PABA, para-aminobenzoic acid is a naturally occurring amino acid that has been studied in the treatment of hair loss. Additional clinical study is needed before a firm conclusion can be made. PABA is typically shown to be safe when used topically in concentrations of 1-15% in adults and children. However, some people may have hypersensitivity to its use, especially children.
- Rosemary : Rosemary (Rosmarinus officinalis Linn.) is a common evergreen aromatic shrub that is grown in many parts of the world. The fresh and dried leaves are used frequently in traditional Mediterranean foods as a flavoring agent and as a food preservative. Historically, rosemary has been used to stimulate the growth of hair. Rosemary oil has been shown to increase circulation and possibly promote hair growth in patients with alopecia areata. Additional study is warranted to confirm these findings.
- Avoid if allergic or hypersensitive to rosemary, its constituents, or members of the Labitae/Lamiaceae family. Use cautiously if prone to atopic or hypersensitivity reactions. Use cautiously with a history of iron deficiency anemia. Use cautiously with coagulation disorders, hypotension, diabetes, or peptic ulcer disease. Use cautiously if taking anticoagulants, antiplatelet agents, anti-hypertensive agents, anti-cancer drugs, medication for high cholesterol, herbs or drugs that are broken down by the liver, diuretics, estrogen or estrogenic herbs, or medications for osteoporosis. Avoid if taking lithium. Avoid if pregnant or breastfeeding.
- Saw palmetto : Saw palmetto (Serenoa repens or Sabal serrulata) is commonly used in Europe to treat symptoms of enlarged prostate. It has been suggested that saw palmetto may reduce inherited male-pattern hair loss, as well as hair loss for women, similar to the medication finasteride (Propecia®). More studies are necessary before saw palmetto can be recommended for this use.
- Avoid if allergic or hypersensitive to saw palmetto. Use cautiously with a history of health conditions involving the stomach, liver, heart, or lungs, hormone-sensitive conditions, or bleeding disorders. Use cautiously with drugs that thin the blood, hormonal drugs, or birth control pills. Avoid if pregnant, possibly pregnant, or thinking about becoming pregnant. Avoid if breastfeeding.
- Selenium : Selenium is a trace mineral found in soil, water, and some foods. Studies report that selenium-containing shampoos may help improve dandruff and selenium is included in some commercially available products.
- Avoid if allergic or sensitive to products containing selenium. Avoid with a history of non-melanoma skin cancer. Selenium is generally regarded as safe for pregnant or breastfeeding women. However, animal research reports that large doses of selenium may lead to birth defects.
- Tea tree oil : The tea tree (Melaleuca alternifolia) is a small tree with narrow, soft, alternate leaves and yellowish flowers the shape of bottlebrushes. It is one of more than 30 species of paperbark trees that are found throughout Australia. Tea tree oil is obtained by steam distillation of the leaves of the tea tree. Preliminary research reports that the use of 5% tea tree oil shampoo on mild-to-moderate dandruff may be effective and well tolerated. Further research is needed to confirm these results.
- Avoid use if allergic to tea tree oil or plants of the Myrtle (Myrtaceae) family, Balsam of Peru, or banzoin. Use cautiously with a history of eczema. Avoid taking tea tree oil by mouth because cases of toxicity have been reported. Avoid if pregnant or breastfeeding.
- Thyme : Thyme is a common herb used in cooking. It has also been used for thousands of years to treat medical conditions. Thyme has been suggested as a possible treatment for alopecia areata. However, further research is needed to confirm these claims.
- Avoid if allergic or hypersensitive to thyme, constituents of thyme, members of the Lamiaceae (mint) family, or rosemary (Rosmarinus officinalis). Avoid oral ingestion or non-diluted topical application of thyme oil due to potential toxicity. Avoid topical preparations in areas of skin breakdown or injury or in atopic patients, due to multiple reports of contact dermatitis. Use cautiously with gastrointestinal irritation or peptic ulcer disease due to anecdotal reports of gastrointestinal irritation. Use cautiously with thyroid disorders due to observed anti-thyrotropic effects in animal research of the related species Thymus serpyllum. Avoid if pregnant or breastfeeding.
- Thymus extract : Thymus extracts for nutritional supplements are usually derived from young calves (bovine). Thymus extract is commonly used to treat primary immunodeficiencies, bone marrow failure, autoimmune disorders, chronic skin diseases, recurrent viral and bacterial infections, hepatitis, allergies, chemotherapy side effects, and cancer. Preliminary evidence suggests that thymus extract may be useful for alopecia and/or hair re-growth. More clinical trials are required before recommendations can be made involving thymus extract for this use.
- Avoid if allergic or hypersensitive to thymus extracts. Use bovine thymus extract supplements cautiously due to potential for exposure to the virus that causes "mad cow disease." Avoid use with an organ transplant or other forms of allografts or xenografts. Avoid with thymic tumors, myasthenia gravis (neuromuscular disorder), or untreated hypothyroidism. Avoid if receiving immunosuppressants or hormonal therapy. Avoid if pregnant or breastfeeding. Thymic extract increases human sperm motility and progression.
- Zinc : Zinc formulations have been used since ancient Egyptian times to enhance wound healing. A few studies that examined the efficacy of oral zinc for the treatment of alopecia reported contradictory results. Additional studies are needed before a conclusion can be made. In addition, shampoo containing 1% of zinc pyrithione has been shown to reduce dandruff in some people.
- Zinc is generally considered safe when taken at the recommended dosages. Avoid zinc chloride, since studies have not been done on its safety or effectiveness. While zinc appears safe during pregnancy in amounts lower than the established upper intake level, caution should be used, since studies cannot rule out the possibility of harm to the fetus.