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134 points gnabgib | 2 comments | | HN request time: 0s | source
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ggm ◴[] No.44450388[source]
In cell cultures. So nothing about topical, or digestive pathways. Just, expose cells to vitamin c rich medium.

How would topical application work, and what kind of homeostasis effect, from ingestion.

If you are low on vitamin c in your diet, sure. If not, you may not get much benefit from having more.

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ethan_smith ◴[] No.44451394[source]
Topical vitamin C (L-ascorbic acid) at concentrations of 10-20% with pH <3.5 can penetrate the stratum corneum, though stability and formulation significantly impact bioavailability.
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jijijijij ◴[] No.44454391[source]
You can just freshly mix cheap vitamin C powder and water to the desired concentration, adjust pH to be less irritating. The solution can last for a few days, if cooled and protected from light. For it to be effective (according to studies), it needs to be applied daily/frequently. However, DIY is so cheap, you can use it all over your body. Wash/wipe off excess (see below).

The problem is commercialization. Vitamin C is very, very reactive, so formulating it for shelf storage and production is challenging. I think you either have to add expensive/exotic antioxidant systems, or rely on ascorbate derivatives which may be less/not effective.

Fair warning: Vitamin C degrades to dehydroascorbic acid: After some delay, vitamin C solution may stain skin and everything in contact yellow. DHA may also further break down into erythrulose, a self-tanning agent browning the skin semi-permanently (likely not very healthy). Vitamin C may also react with other things (eg. skin care products) in unpredictable ways and can actually form radicals under some conditions. Eg. It can react with benzoic acid to form benzene. On the modern skin, with UV exposure, a primordial soup of "actives", complex hydrocarbons and all natural metal catalysts, vitamin C may facilitate genesis…

The science is promising, but the chemistry of vitamin C is hard to control, or even reason about.

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inkyoto ◴[] No.44454533[source]
> The problem is commercialization. Vitamin C is very, very reactive.

… hence it oxidises easily.

There has recently been a novel development, ethyl ascorbic acid, that is much more stable due to being more inert. It resists the oxidation for a much longer time compared to ascorbyl glucoside and L-ascorbic acid, and it has been successfully commercialised in some skincare products. The products using it command a premium, though.

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jijijijij ◴[] No.44454810{3}[source]
AFAIK, the derivatives are less researched, so hard to argue about. Often, the concentration isn’t disclosed, too.

I would just go DIY, since commercial products are either very, very expensive, or ineffective. Once you got your measurements down, mixing it freshly takes no time. And you can afford to use it all over the body, not just the face. This way you know, it’s not oxidized, it’s exactly what’s used in some better studies, it is effective. Even DIYing a stabilized formulation with ferulic acid is possible and still much cheaper.

Personally, I have trust issues with vitamin C chemistry tho :D

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1. gamblor956 ◴[] No.44461180{4}[source]
Anyone who can afford the equipment to make fresh vitamin c serum could easily afford several years supply of high end commercial products that have been tested to confirm their ingredients and effects.
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2. jijijijij ◴[] No.44463253[source]
That’s ridiculous.

You need a mg scale and pH strips as equipment (~ 20€, once); tap water, pure vitamin C and sodium bicarbonate as ingredients (~ 6€, lasts for many, many preparations). Aluminium foil to make any glas container light-tight.

The chemicals are food grade from your next supermarket or drug store. The "recipe" is used in some studies.