can a raw onion reduce hair loss
Can a raw onion reduce hair loss


Onions (Allium cepa L.) are excellent sources of vitamin C, flavonoids, sulphuric compounds and phytonutrients.

Vitamin C is an antioxidant that is essential for the maintenance of connective tissue and protein metabolism.

Flavonoids are responsible for the pigments in many fruits and vegetables and are are known to possess hair growth promoting properties [1].  Two flavonoid sub groups can be found in onions, the anthocyanins, which impart the purple/ red colour to red onions and flavanals such as quercetin, these act as antioxidants and provides certain hair health benefits.

The sulphuric compounds in onions are disulphides, trisulphides (collectively known as cysteine sulphoxides), these sulphides can react with components of the scalp such as the proteoglycans and glycosaminoglycans that contribute to the regulation and growth of the hair follicle [2].


Onions are a major provider of essential nutrients and bioactive compounds.  Sulphides in onions acts as a sulphur donor that assists with detoxification, protein synthesis and the building of cell structures.  Onions also contain fibre, potassium, iron, calcium and folic acid.  Onions are healthy whether they  are eaten raw or uncooked, though raw onions will provide higher levels of sulphur compounds.  A study by the Journal of Agricultural and Food Chemistry found there were higher concentrations of flavonoids in the outer layers of onion flesh.


  1. Digestion of fat soluble vitamins – The sulphur content in onion contributes to bile production and the uptake of fat-soluble vitamins.  Fat soluble vitamins like vitamin A, vitamin D, vitamin E and vitamin K are integral to hair follicle health.
  2. Anti-inflammatory – Sulphur compounds have anti-inflammatory and antioxidant effects.  The polyphenols in onions act as antioxidants against free radicals.  Antioxidants disturb the growth and repair capacity of the cell and decreases glutathione which is the cells major reservoir of cysteine.  Cysteine and methionine are the only sulphur donating amino acids and low levels of cysteine reduces the density of the hair fibre and the capacity of the hair cycle for growth.  Once the cysteine reservoir in the cell has been depleted, the cell will struggle to produce keratins, the major building blocks of the hair.
  3. Gut health – Onions contain oligofructose, a type of prebiotic fibre that feeds the ‘good bacteria’ our gut.  The consumption of prebiotic fibres will increase levels of Bifidobacterium and Lactobacillus in the gut.  The correct balance of gut bacteria is needed for a healthy immune system.  An imbalance of ‘good’ and ‘bad bacteria’ can lead to conditions such as alopecia areata.
  4. Regulation of blood sugar – The chromium in onions assist in regulating blood sugar.  A study in 2014 in the Journal Nutrition found that patients with Type II diabetes saw lower blood sugar levels and normalised liver enzymes when consuming raw sliced onions [3].  The hair follicle is subject to oxidative damage when blood sugar levels are too high.  When there are high levels of circulating insulin, vascular resistance increases and blood flow to the scalp is reduced.


Eating raw onions can cause some minor side effects for some.  The carbohydrate content of onions can cause bloating and excess gas for this with a non-specific carbohydrate intolerance.  Raw onions can also increase the severity of heartburn in those with chronic heartburn and gastric reflux disease.  It is also possible to have a specific allergic reaction or a food intolerance to onions, though this is rare.  People with onion  allergies  can experience rashes or itchy eyes.  An intolerance to onions may result in vomiting, nausea and other gastric issues.


Whilst there are no clinical trials that determine how many onions you should eat per day it may be wise to add a raw onion salad to your diet once or twice a week.  Mix your onion salad with meat, fish or veg for a complete meal and consider adding yoghurt and other condiments.

Nutrition facts (1 medium onion / 143 grams), total carbohydrate 11 grams (4% DV), dietary fibre 3 grams (12% DV), potassium 190 milligrams (5%), protein 1 gram; vitamin C (20% DV), calcium (4%DV), iron (4%DV).

*DV = Daily value based on 2000 calories

Red onion Indian salad – Slice 4 red onions thinly and mix with 4 tablespoons of greek yoghurt.  Add 1 teaspoon of chilli powder, 2 teaspoons curry powder.  Add 1 teaspoon of salt and one teaspoon of pepper.  Add 6 teaspoons each of chopped mint and coriander.  Add 6 teaspoons of lime juice, 6 teaspoons of rice vinegar.  Mix until combined.  Will keep in the fridge for around 5 days.

Red onion Turkish sumac salad – Slice 4 red onions thinly and mix with 1 teaspoon of sumac, 1 teaspoon salt.  Add 1 teaspoon red pepper flakes and a half a cup of parsley.  Add 2 tablespoons of lemon juice and 4 tablespoons of olive oil.

White onion and cucumber salad – Slice 1 onion thinly and 3 cucumbers.   Mix with half a cup of apple cider vinegar and 4 tablespoons of olive oil and 4 tablespoons of water.  Add 2 tablespoons of dill and and salt and pepper to taste.


  1. Rambwawasvika, H., Dzomba, P. and Gwatidzo, L., 2019. Hair growth promoting effect of Dicerocaryum senecioides phytochemicals. International journal of medicinal chemistry, 2019.
  2. Griffiths, G., Trueman, L., Crowther, T., Thomas, B. and Smith, B., 2002. Onions—a global benefit to health. Phytotherapy research, 16(7), pp.603-615.
  3. Akash, M.S.H., Rehman, K. and Chen, S., 2014. Spice plant Allium cepa: Dietary supplement for treatment of type 2 diabetes mellitus. Nutrition, 30(10), pp.1128-1137.