Apple cider vinegar (ACV) has become a popular ingredient in natural hair care routines, with many people claiming it leaves their hair shinier, smoother, and easier to manage. But does leaving it in overnight really deliver better results—or could it do more harm than good?
While diluted apple cider vinegar may offer some benefits when used as a short rinse, leaving it on your hair or scalp overnight is generally not recommended. Its acidity can irritate the scalp, especially for people with sensitive skin or existing scalp conditions.
Here’s what you should know before trying this popular hair care trend.
Why Is Apple Cider Vinegar Used on Hair?
Apple cider vinegar contains acetic acid, which gives it a naturally low pH. Hair products, hard water, and product buildup can sometimes leave hair looking dull or feeling rough. A properly diluted ACV rinse may help remove some buildup and smooth the outer layer of the hair (the cuticle), making hair appear shinier.
People use ACV rinses in hopes of:
- Adding shine
- Reducing product buildup
- Helping detangle hair
- Making hair feel softer
- Refreshing the scalp
However, scientific research on ACV specifically for hair is limited, and many claims are based on personal experiences rather than strong clinical evidence.
What Happened When I Tried It?
Like many DIY beauty enthusiasts, I was curious after reading countless success stories online. Some people claimed their hair became incredibly soft after leaving diluted apple cider vinegar on overnight.
I decided to give it a try.
I mixed apple cider vinegar with water, applied it to my scalp and hair, covered my pillow with a towel, and went to sleep expecting to wake up with salon-worthy hair.
The next morning, I noticed a few changes.
My Hair Felt Cleaner
After washing it out, my hair did feel lighter and cleaner, likely because the vinegar helped remove some residue from styling products.
There Was More Shine
Once my hair dried, it appeared shinier than usual. This may be because the acidic rinse temporarily smoothed the hair cuticle, allowing it to reflect more light.
The Smell Wasn’t Pleasant
Even after rinsing, a faint vinegar smell lingered for a while. Although it eventually faded, it wasn’t my favorite part of the experience.
My Scalp Felt Sensitive
The biggest surprise was that my scalp felt slightly dry and irritated afterward. This reminded me that apple cider vinegar is acidic, and leaving it on for hours may not be suitable for everyone.
Is It Safe to Leave Apple Cider Vinegar on Overnight?
For most people, it’s better not to leave apple cider vinegar on your scalp overnight.
Potential risks include:
- Scalp irritation
- Dryness
- Redness
- Burning sensations
- Damage if used undiluted
People with eczema, psoriasis, cuts, or a sensitive scalp should be especially cautious.
A Safer Way to Use Apple Cider Vinegar
If you’d like to try an ACV rinse, use it as a brief treatment instead of an overnight application.
You’ll Need
- 1–2 tablespoons of apple cider vinegar
- 1 cup of water
Directions
- Shampoo your hair as usual.
- Pour the diluted mixture over your hair and scalp.
- Leave it on for 2–5 minutes.
- Rinse thoroughly with cool or lukewarm water.
- Follow with conditioner if needed.
Always perform a patch test first, especially if you have sensitive skin.
Who Should Avoid Apple Cider Vinegar Hair Treatments?
You may want to skip ACV rinses or consult a dermatologist first if you have:
- A sensitive scalp
- Open cuts or sores
- Severe dandruff
- Eczema or psoriasis affecting the scalp
- Recently colored or chemically treated hair that is prone to dryness
Other Ways to Keep Hair Healthy
Healthy hair depends on more than one ingredient. Consider these habits:
- Wash your hair with a shampoo suited to your hair type.
- Use conditioner regularly to reduce dryness.
- Limit excessive heat styling.
- Protect your hair from sun exposure when possible.
- Eat a balanced diet rich in protein, iron, zinc, and vitamins.
- Stay hydrated.
- Trim split ends regularly.
The Bottom Line
Apple cider vinegar may help remove product buildup and temporarily improve shine when properly diluted and used as a short rinse. However, leaving it on your hair or scalp overnight is generally not recommended, as it may cause irritation, dryness, or discomfort—especially for people with sensitive skin.
If you’re curious about trying an ACV rinse, use it sparingly, dilute it well, and pay attention to how your scalp responds. Sometimes, less really is more.
Disclaimer: This article is for informational purposes only and should not be considered medical or dermatological advice. If you experience persistent scalp irritation, hair loss, or other concerning symptoms, consult a qualified healthcare professional or dermatologist.