I love my coffee. Correction: I NEED my coffee. The bigger the cup, the better I function.
However, one too many selfies made me realize that my teeth are getting ugly yellow stains from all my coffee indulgence.

Of course, the coffee addict in me refuses to give up my only source of happiness (oof), leaving me to battle my teeth discoloration with whitening products.
After hours of YouTube and Reddit reviews, I decided to order my first box of Crest 3D Whitestrips from Amazon. Got it within a week and was super excited to experience the magic that people are raving about.

Holey Molar does it HURT!!
To my dismay, my gums were burning and irritated within the first 5 minutes. Despite the instructions saying that I had to leave the strips on for about 20 minutes, I ripped mine off in less than 10.
The auntie in me is very upset at the fact that I just spent $50 on a product that hurts. The scientifically literate in me wants to find out what is in this product that is torturing my gums.
A quick look at the ingredients list on the box shows that the main active ingredient is hydrogen peroxide, aka H2O2. Hydrogen peroxide is a common bleaching chemical found in bleaches for hair, clothes, underarms, b*ttholes (wait whut), etc. It is also a well-known oxidising agent that can be bought over the counter at your neighbourhood Watsons and Guardians.
Tooth stains consist of chromogens, which are large organic compounds that have conjugated double bonds in their chemical structure. An example of chromogen is β-carotene. If conjugated double bonds are present, it means that the molecules have a series of alternating single and double bonds. An example of a molecule with conjugated double bonds that you may be familiar with is the benzene ring.

Oxidising agent hydrogen peroxide present in the whitening strips adds oxygen atoms to the carbon double bonds, converting them to single bonds. This is also known as an oxidative addition reaction. The resulting products are molecules that reflect less light, resulting in a reduction of teeth discoloration.

Hydrogen peroxide oxidation of carbon double bonds.
Unfortunately, the very ingredient that helps whiten my teeth is also the culprit of the burning sensation in my gums. Hydrogen peroxide at high concentration of more than 10% is corrosive. It oxidises the proteins, membrane and DNA present in our cells, causing them to lose their structures, eventually leading to cell death.
You would think that with this information, teeth whitening companies will play it safe and make products with hydrogen peroxide concentration way below 10%. But oh boy were we wrong. The Crest 3D Whitestrips I was using contain TEN percent hydrogen peroxide. Not only that, I found out they have another version that contain FOURTEEN percent hydrogen peroxide. (hello polis?)

I cannot comment on the effectiveness of the whitestrips as I only used them once, for less than 10 minutes. I also do not see myself using them again, having to go through the excruciating pain. Sigh, $50 gone just like that. I guess I only have myself to blame. I should have done my scientific research before buying teeth whitening products.
But hey, good news is we are in a strange era where we must cover the lower half of our faces wherever we go. Teeth whitening can take a back seat for now. And my Crest 3D Whitestrips can find a cushy spot deep inside my drawers…