Does artificial sweetener reduce the pH of hair dye?
Posted Apr 23 2013 2:02am
Lynsey says…I have been a hairdresser for six years and a cosmetology teacher for two. While I have used this trick a few times (and even have Equal stashed in my color bar), I never knew why it worked either. I did a little research about the pH of aspartame and bingo: it changes the pH of the chemical reaction during a color process.
Aspartame, when mixed in a solution, is highly acid producing (one of the reasons Diet Coke eats the enamel off your teeth). When mixed into the alkaline emulsion of hair color plus peroxide, it effectively neutralizes the solution. The acid produced by the aspartame reduces the irritation of a highly alkaline process.
The only effect I can see this having on hair color is that the color may not stick. An alkali solution is needed to fully lift the cuticle and admit the color molecules. An acid (like a conditioner or hair mask) is applied afterward to seal the color in by collapsing the cuticle.
Love your blog and glad to see someone else nerding it up over beauty!
The Beauty Brains respond:
Lynsey’s comment originally appeared on our post on “Can you make hair dye less irritating by mixing it with artificial sweetener” but we thought it raised an important enough point to justify a follow up blog post. But first we have to give a shout out to Lynsey: Thanks for your kind words about the blog. We’d be nothing without fans like you. And as a fan, we hope you’ll appreciate the message of today’s post which is that you shouldn’t believe everything you read unless it’s presented with reliable data!
Case in point, Linsey’s comment about aspartame being highly acidic. This sounded a little off to us because aspartame would have to be VERY acidic to act as she described. So, rather than rely on Internet information, we did some old school science and collected data ourselves.
In this case the data is the pH of a solution of aspartame. If what Linsey says is true, this solution should be very acidic. Luckily, expensive equipment isn’t needed to collect pH data – anyone can measure pH using paper strips that cost about about ten bucks. So we poured some Equal into water and tested the pH of “aspartame in solution.”
These pH strips change color to match a specific pH. As you can see from the picture above, when we dipped the strip into the aspartame solution the resulting pH is very close to 7.0 which is neutral. This is a LONG way from being “very acidic” which would require the pH to be below 4 (probably closer to 2 or 3.)
With all due respect to Linsey, the data shows that her statement is simply not true. Aspartame is NOT acidic. But why then, is Diet Coke so acidic that it “eats the enamel off teeth?” Well, since we’re not the “Dental Brains” we won’t comment on the enamel dissolving properties of Diet Coke but a quick peek at the ingredients shows this particular diet soda contains both phosphoric acid and citric acid. Now THOSE ingredients will lower pH!
Our “religion” is science and we preach that you should be skeptical, that you shouldn’t believe everything you read, and that you should look for corroboration from primary data or multiple reputable sources. In this case, anyone can verify what we’ve said by spending few bucks on pH strips: Aspartame is NOT acidic enough to lower the pH of hair dye. Q.E.D.