Putting anything topical on your hair (non-medical), will not make your hair grow any faster, longer or thicker than it would if you didn’t. There are some realities and some possible advantages of D.I.Y. treatments though, and I’m here to tell you what’s what.

To understand how these treatments work, we first need to take a look at our scalp:
Your scalp is covered in hundreds of thousands of hair follicles, and surrounding these hair follicles are sebaceous (oil) glands that help protect the follicles, as well as the skin around it from things like infection, parasites, etc. Your hair and scalp are their own eco system, providing the best conditions for your hair to grow. Both the skin on your scalp and your hair have a potential hydrogen (or PH) level of 4.5-5.5, which means that hair is a bit more acidic in nature than neutral (7.0). When you wash your hair, you are putting a cleansing agent (shampoo) on your hair and scalp with either a higher or lower PH than 4.5-5.5, which makes it able to strip away the natural oils from your scalp, and also loosen any sort of dirt or debris from your strands. Have you ever noticed that while you’re rinsing the shampoo out of your hair your hair feels squeaky-clean? This is because the PH balance has been altered. Conditioner, contrary to what most people believe, is actually not used for moisture purposes, but to correct the PH back to the normal 4.5-5.5. This is why you should use a corresponding conditioner to your shampoo’s PH level to ensure proper balance.
Every time you wash your hair, it resets your scalp’s eco system, causing your body to over compensate for the lost natural oils with excess production. This is why the more you wash your hair, the greasier it gets between washes- your scalp is anticipating that cleansing, and preparing to compensate.

All that being said, here is a simple answer for all of the D.I.Y. hair treatments out there:

1. Apple cider vinegar, onion juice, banana, yogurt, avocado, beer (and many more) hair masks/rinses
Have you ever heard your grandmother use the term “Acid Rinse”? Back in the day, this is what they referred to conditioner as, which as I explained above, is kind of a more accurate name anyways. Your hair has a PH of 4.5-5.5, so if you rinse it with apple cider vinegar or beer (both are acidic, scoring around 4-6 on the PH scale), it can help your hair and scalp return to a normal PH after doing something that caused an alkaline swing, like swimming or over washing. But conditioner does the same thing- and your hair won’t smell like India Pale Ale when you’re done. The same can be said for onion juice and yogurt- they’re simply acidic in nature.

2. Avocado/banana/oil-type moisture masks may be acidic in nature, but they aren’t providing your hair with any sort of vitamins or minerals… Hair grows from the inside out! However, avocado oil, which can be found in the mashed-up pulp that you are putting on your hair, may have some benefits to your strands; the molecular size of avocado oil is similar to the natural sebaceous oil secreted on to your scalp, which is small enough to penetrate into your hair strand, and can provide a fatty acid layer that essentially moisturizes your hair like putting absorbent lotion on your skin will. The same can NOT be said for any large-molecule oil, like olive, coconut, grapeseed, etc. Those oils will sit on top of your hair strand, coating your strand instead of absorbing into it, and attracting dirt and other debris that stick to it*. Small molecule oils are found in most professional hair care products- Argan and almond oils good for moisturizing your strands and won’t cause a greasy build up, so realistically, there is no reason for you to put that fruit mask on your head.

*Large molecule oils can be good for people with ethnic hair, and here’s why:
Large molecule oils can act like an anti-humectant, which means the prevent water from penetrating past them, much like how if you pour water into a glass of oil, the oil will rise to the top (also because it’s less dense than water), and form a layer that is keeping the water underneath it. Anti-humectants can be beneficial for people with ethnic hair, as ethnic hair expands nearly twice as much as non-ethnic hair when exposed to humidity. Ethnic hair is coarser, and often more textured than non-ethnic hair, so adding a coating of slick oil can also make it more manageable to style. That being said, it shouldn’t be applied to wet hair, as it will probably never dry all the way for the same reason- it traps water inside the hair strand. Many professional ethnic hair styling products contain large molecule oils like olive, and if they work, they work… However, other types of anti-humectants are added into ethnic hair (as well as non-ethnic hair) products to do the same thing (think anti-humidity hairspray), and won’t be as oily. The bottom line is that if you have ethnic hair, (not you folks with the Latin/Middle Eastern/Asian/Islander hair, I mean black hair- a fro, or some really spongy, nappy hair) choosing products with large molecule oils can be your friend.

Please don’t put food on your scalp; use a good shampoo and conditioner, wash sparingly, and exercise the blood vessels on your scalp and keep your strands clean by brushing twice a day. If your hair feels dry, use a small molecule oil on the mid-strands/ends of your hair to provide a little help, but if your scalp is dry, check the P.H. level of your shampoo and conditioner, and be patient young padawan.