Leaving apple cider vinegar (ACV) in your hair overnight is a popular home remedy, but the claims online are often overstated.
Here’s what ACV can do:
- Remove product buildup: Its acidity may help dissolve residue from styling products or hard water.
- Make hair look shinier: Smoothing the hair cuticle can increase light reflection.
- Reduce scalp itchiness: Diluted ACV may temporarily help some people with mild dandruff or an itchy scalp by changing the scalp’s pH.
- Improve manageability: Hair may feel smoother after a rinse.
However, leaving it on overnight is generally not recommended because:
- Even diluted ACV is acidic and can irritate the scalp, especially if you have sensitive skin, eczema, or small cuts.
- It may dry out your hair and scalp if used too often or at too high a concentration.
- There is no strong scientific evidence that overnight ACV treatments promote faster hair growth or permanently repair damaged hair.
A safer way to use ACV is:
- Mix 1–2 tablespoons of apple cider vinegar with 1 cup (240 mL) of water.
- After shampooing, pour it over your hair and scalp.
- Leave it on for 2–5 minutes.
- Rinse thoroughly with cool or lukewarm water.
- Use it no more than once a week to start.
If you notice burning, redness, or increased hair shedding after using ACV, stop using it and wash your scalp with water. If scalp symptoms persist, it’s a good idea to consult a dermatologist.
So, while ACV may leave your hair feeling cleaner and shinier, the dramatic “overnight transformation” stories you see online are not well supported by scientific evidence.
