The Best Vitamin for Natural Hair Growth?

There is no mistaking the current trend in the cosmetics industry to
incorporate vitamins and plant derivatives into formulations in order to
advertise products as healthy, natural, green, sustainable or
possessing anti-aging properties. One popular claim suggests using
vitamin C for hair growth. As an essential nutrient for health, vitamin C
takes part in many cellular processes and must be ingested by humans in
significant quantities as we do not manufacture it internally as some
other species do. Centuries ago, it was common knowledge that deficiency
in this nutrient (later identified as vitamin C) among sailors on long
voyages and the malnourished poor caused a horrible condition known as
scurvy. The condition was determined to be easily preventable with the
consumption of relatively small amounts of fruit or vegetables that had
abundant levels of vitamin C. It is critically important for optimal
function of the immune system and for tissue growth regeneration.
Clearly, vitamin C is well-established as a necessary substance for
internal consumption. But, does it really have any benefits when used
externally in skin and hair?

Vitamin C in Beauty Products

Perhaps not surprisingly, the answer is sometimes yes, sometimes no.
Vitamin C is a popular component of many topically applied skin care
products, where it has definite observed benefits when used above
certain concentrations (5-15%). At the surface, it acts as an
anti-oxidant, combating damage caused by free radicals created by
environmental pollutants and ultraviolet radiation exposure. This can
help prevent formation of new wrinkles that occur when free radicals are
present on skin. Vitamin C has also been shown to penetrate and
transfer to epidermal tissue where it aids in cellular repair and
promotes collagen production. It is beyond the scope of this article to
explore all of the mechanisms and variables by which vitamin C benefits
skin, but clearly, it does provide some genuine value. Whether or not it
provides benefits to hair is less dependent upon complicated cellular
processes and more dependent upon some basic chemical properties.

Chemical Structure

Vitamin C is the common name for ascorbic acid, a small chiral
molecule, in other words one that can occur in two different forms that
are non-superimposable mirror images of one another. The type of
ascorbic acid found in plants, synthesized in animals and used in
cosmetic and food products is the left-handed molecule (levorotatory
enantiomer) of ascorbic acid (L-ascorbic acid). For whatever reason, the
right-handed version (dextrorotatory) does not occur in nature and the
lab-synthesized version offers no benefits over its more readily
available isomer.

Properties and Benefits

Vitamin C is a small molecule organic acid, with key structural
features in common with other mild acids, such as acetic acid (vinegar)
and citric acid. For this reason, ascorbic acid can act as a mild
clarifying agent in shampoo and can be effective in helping remove
mineral buildup accumulated on the surface of the hair. This improves
the ability of the hair to accept moisture, which makes it more soft and
supple and resistant to tangling and breakage. Also, the lower pH of
acidic shampoos smoothes and tightens the cuticle surface, rendering the
hair more evenly reflective and shinier.
The presence of multiple hydroxyl groups (oxygen-hydrogen, -OH) makes
ascorbic acid extremely hygroscopic, meaning it attracts and binds
water to itself. For this reason, vitamin C can act as a humectant and
effective moisturizer in hair products when used in conditioners,
leave-in conditioners and styling products.

Also, when included as a component in leave-in conditioners and
styling products, vitamin C can act as an anti-oxidant, much in the same
manner as in skin creams. Free radicals can cause structural damage to
the proteins in hair, which can lead to split ends and breakage. They
also can react with both natural melanin and synthetic dye molecules
resident in the cortex of the hair strands and bleach color from hair,
while simultaneously causing physical damage to it. For this reason,
free radical scavengers, such as vitamin C can be quite useful in color
retention and maintaining the health and integrity of hair. Ascorbic
acid is water soluble and is thus not a concern for build up or
accumulation on the surface of hair, even when non-mainstream cleansing
methods are employed (low-poo, no-poo).

Oftentimes, vitamin C is used as a preservative or pH adjuster in
hair care products and has no significant impact at all on final
properties of the product. If it appears as one of the last few
ingredients, below what is known as the one-percent line, you can be
assured that this is the case.

Vitamin C for Hair Growth

The marketing materials for some hair care products claim that their
vitamin-C containing formula can promote hair growth and repair an
unhealthy scalp. While it is certainly true that ascorbic acid is
capable of transfer to tissue and cells in specifically-formulated skin
care products where it can participate in cellular processes, this isn’t
usually the case in shampoos and conditioners. The reasons for this are
that the pH of hair care products is generally too high for the acid to
be active and the concentration of the ascorbic acid is too low for
there to be any benefit. For this reason, most of these types of
products will have no significant impact to the scalp or hair growth.
However, it is possible that a formula intended for direct skin
application might be of some benefit to the scalp tissue. Whether this
would promote hair growth is not certain, but a healthy scalp is in the
best position to perform this function. This would probably fall into
the category of “it couldn’t hurt to try in moderation.”

Final Thoughts

Some users have reported that some vitamin C-based products have felt
drying to their hands and hair. This is going to be very dependent upon
an individual’s hair and skin type as well as on the other ingredients
in the formulation. It is doubtful that the vitamin C itself leads to
dryness, but perhaps if coupled with harsh surfactants, a too-low pH or
insufficient emollients and moisturizers, a product could produce that
undesirable tactile feel. Always trust your own reaction to a product
and use what works for you!