That headline is clickbait. There isn’t good scientific evidence that leaving apple cider vinegar (ACV) in your hair overnight produces dramatic results, and it may actually irritate your scalp.
Here’s what ACV may do when used properly:
Potential benefits
- Remove some product buildup and hard-water residue.
- Make hair appear shinier by smoothing the hair cuticle.
- Help reduce mild scalp itchiness or flakes in some people.
Potential risks of leaving it on overnight
- Scalp irritation or burning, especially if it’s not diluted.
- Dryness of the hair and scalp.
- Worsening of eczema or sensitive skin.
A safer way to use ACV
- Mix 1–2 tablespoons of apple cider vinegar with 1 cup (240 mL) of water.
- After shampooing, pour the mixture over your hair and scalp.
- Leave it on for 2–5 minutes.
- Rinse thoroughly with water.
- Use it about once a week to start.
What ACV won’t do (despite online claims)
- It won’t permanently repair damaged hair.
- It won’t reliably make hair grow faster.
- It won’t cure dandruff or scalp conditions.
If you experience burning, redness, or persistent irritation, stop using it and wash your hair thoroughly. If symptoms continue, consult a healthcare professional or dermatologist.
In short, ACV can be a useful occasional hair rinse for some people, but overnight treatments are not recommended, and the dramatic transformations often claimed in viral posts are not supported by strong scientific evidence.
