Lemons have citric acid and can be used to naturally lighten your hair, though it works best in lighter hair tones. But using lemon juice topically may irritate your skin or cause a contact reaction.

The potential uses of lemons go beyond flavoring water and culinary dishes. This popular citrus fruit is a good source of vitamin C, which can boost your immune system and reduce inflammation.

Lemons also have bleaching properties, which is why they’re often found in cleaning and skin care products.

When it comes to your hair though, lemons are most beneficial when applied topically in liquid form. Lemon juice can be used to:

  • naturally lighten hair, especially lighter hair colors
  • create shinier hair
  • reduce oil and dandruff

If you’re thinking about using lemon on your hair, read on to learn how it works, as well as the potential drawbacks and side effects.

If you search for natural hair lighteners online, you’ll likely come across anecdotal articles about lemon’s lightening effects on your hair.

According to these articles, the citric acid in lemon juice is a natural bleach, or oxidizing agent. It whitens hair by chemically reducing your hair’s color pigment, or melanin. When exposed to the sun, the citric acid accelerates the bleaching process.

The lightening effects of lemon juice tend to work best for lighter hair colors, such as blonde and light brown. Darker brown and black tones might see some of the effects, but they won’t be as noticeable.

To lighten your hair with lemon juice, try one of these three methods:

  • Dilute fresh lemon juice in water and rinse your hair with it.
  • Mix a few drops of lemon essential oil in a carrier oil and glass of water and apply to your hair.
  • Crush vitamin C tablets and add them to your shampoo for a more gradual lightening effect.

No matter which method you use, you’ll see the most results after your freshly lemon-infused hair has seen some sunlight.

No matter what color your hair is, lemon juice can make it look shinier, especially after you’ve been in the sun.

For best results, add 2 tablespoons of apple cider vinegar to the lemon juice rinse of your choice (see options above). Evenly distribute through your hair and let it sit for a few minutes before applying conditioner and rinsing out.

The benefits of citric acid in lemons can even address the root of your hair problems — literally. This is especially true if you have a dry scalp or dandruff.

When you apply your lemon juice hair rinse, make sure you massage the mixture into your scalp, too. If you have a type of dandruff called seborrheic dermatitis, lemon juice may help absorb excess oils that lead to this common scalp condition. Such effects can work for all hair colors.

Fresh lemon juice will not dry out or damage your hair. However, prolonged exposure to the sun can damage your hair’s outer sheath, called the cuticle. For this reason, you’ll want to limit the amount of time you spend in the sun after applying lemon juice to your hair.

Try sitting in the sun just until the lemon juice has dried — no more than one hour — then rinse and apply a conditioner to your hair. You can also try adding a teaspoon of oil to your lemon juice solution for added protection.

May cause skin irritation

Anecdotal evidence suggests that lemons can help treat dry skin and dandruff. However, you’ll want to use caution here, especially if you have eczema or psoriasis. Citric acid may be too powerful and cause skin irritation. You’ll want to discontinue this process if you start to experience redness, increased irritation, and itchiness.

May cause contact reaction

Another possibility is a condition called phytophotodermatitis, which is a contact reaction to certain plants. The reaction is marked by inflammation and blisters, followed by spots of dark pigmentation on the skin that can last for several weeks.

Lemons — and other plants such as oranges, parsley, and parsnips — can cause this condition in some people. While it can’t affect your hair, phytophotodermatitis may affect your scalp, especially if it’s exposed to the sun.

Best practice: Do a patch test

One way to avoid irritation and possible phytophotodermatitis is to conduct a skin patch test a few days before using lemon in your hair and scalp.

To do a patch test, apply a small amount of the lemon rinse you plan on using to your skin. Choose an inconspicuous area, such as the inside of your elbow. If no reaction occurs, the rinse is likely safe.

The citric acid in lemons alone can make your skin more sensitive to the sun. You’ll want to use caution when sitting outside after you’ve applied lemon juice to your hair, especially if any part of your scalp is exposed.

You may consider applying sunscreen to any exposed areas, such as your hair part. Conditioners with zinc oxide can also help protect your hair color and your scalp from harmful UV rays.

Lemons are rich in vitamin C, soluble fiber, and beneficial plant compounds. These nutrients may provide numerous health benefits, including aiding weight loss and reducing your risk of:

  • heart disease
  • anemia
  • kidney stones
  • digestive issues
  • cancer, according to anecdotal evidence

But can drinking fresh lemon juice improve the health of your hair? No current studies exist that prove this connection. However, given the numerous other proven health benefits that lemons can provide, it certainly can’t hurt to add this fruit to your diet.

Due to their citric acid content, lemons can be used to naturally lighten your hair according to anecdotal evidence. However, this method tends to work best in lighter hair tones.

In addition, lemon juice applied topically may pose some risks such as skin irritation or a contact reaction. Consider doing a patch test on your arm before applying to your hair and scalp.

If you want to achieve a specific tone of highlights, see a hairstylist for advice. You should also see a dermatologist if you experience any adverse effects after using a lemon rinse.