Azelaic, Tranexamic, Kojic Acid... The Chemists' Best Hyperpigmentation Ingredients Guide

First Posted on September 29, 2023 in:skincare fundamentalsdecoding activeshyperpigmentation

Uneven skin tone, post-inflammatory hyperpigmentation, dark spots, sun spots, acne scars, melasma… it doesn’t matter what type of hyperpigmentation concern you have, this is one of THE most stubborn skin concerns to tackle. This is an arena where you don’t just need one single BEST ingredient, but a whole family of clinically validated hyperpigmentation-busting ingredients. So let’s go through some of the ingredients you’ll likely come across in your quest to brighten, even skin tone, and tackle stubborn dark spots. In this blog post, we’ll focus on ingredients that you’ll likely come across the most when shopping in this category: azelaic acid, tranexamic acid, kojic acid, brightening plant extracts (licorice roote, bearberry), and more!

Azelaic Acid

Azelaic acid can come off sounding like a “miracle” ingredient because of its link to acne care and even rosacea, but it also has clinical evidence in treating hyperpigmentation. There are two notable studies of using azelaic acid for hyperpigmentation we want to highlight here. In one study, a 20% azelaic acid cream was applied twice daily compared to an active-less vehicle cream for 24 weeks. During this time, study subjects saw continuous improvement over the entire 24 weeks while the vehicle cream did not show the same improvement. Another great study compared 20% azelaic acid to hydroquinone. 20% azelaic acid performed similarly to 4% hydroquinone and outperformed 2% hydroquinone.

How to Add Azelaic Acid to Your Routine

Azelaic acid can be a pain for us chemists to work with. Clinical evidence on this ingredient all involve higher concentrations of 15% to 20%, yet the solubility of azelaic acid is quite poor. This is why you’ll find most azelaic products like The Ordinary’s 10% Azelaic Acid suspension or Paula’s Choice 10% Azelaic Acid booster in a white paste suspension or emulsion. This is why we would suggest putting this in your routine after your lighter toners, serums hydrator steps and before your moisturizer. Because azelaic acid is capped at 10% for cosmetic use despite being tested at much higher levels, we recommend using this both AM & PM to get the most out of this active. 

Tranexamic Acid

Tranexamic acid has truly risen in popularity in recent years. But did you know! It actually came from the medical field as a drug used to help blood clot and prevent excessive bleeding (think… exceedingly heavy periods). But people soon realized that this medicine seems to have the pleasant side effect of brighter, more even skin tone. Initially, oral tranexamic acid (and even locally injected tranexamic acid!) was tested as a treatment for melasma. In more recent years, topical tranexamic acid was also validated as an effective skin brightener. One such study looked at a 2% tranexamic acid product over 12 weeks on 23 patients with mild melasma. Tranexamic acid was effective at brightening overall skin tone and decreasing the melasma area. The most interesting thing here is that the improvements appear to be significant by week 4 - a relatively short time frame from pigmentation studies!

How to Add Tranexamic Acid to Your Routine

Tranexamic acid is actually less fussy for formulators to work with, which is why you often find them in all sorts of formulas from watery toners to even emulsion/lotion textures. You’ll typically find it as part of a cocktail of actives in many hyperpigmentation serums. Lighter formats such as The Inkey’s Tranexamic Acid Hyperpigmentation Treatment, Farmacy’s Brighten Up 3% TXA toner, and Naturium’s Topical 5% Tranexamic Acid should be used as the first step after cleansing both AM and PM.

Kojic Acid

Kojic acid is a naturally-occuring compound found in several fungi. It’s also one of the byproducts of the sake fermentation process. Though kojic acid has a long history of use and a reputation as an effective skin brightener, there isn’t a LOT data on this one. In fact, kojic acid is usually tested in conjunction with other well-known whitening actives. Most notably, it seems to work well when combined with glycolic acid. Skinceutical’s Discoloration Defense uses 1% kojic acid alongside tranexamic acid and niacinamide. Discoloration Defense was clinically tested specifically on darker skin tones (Fitzpatrick scale IV to VI) and was effective at evening out skin tone without side effects.

How to Add Kojic Acid to Your Routine

This water-loving ingredient is often found in lightweight serums. So we would keep this as one of the first steps in your routine alongside your favorite hydrating serum. Beware! Kojic acid is another finicky ingredient that loves to degrade. Store at vampire conditions, and when it gets about 3 shades darker or even black… it’s time to let it go. This isn’t something you should rely on as a solo active ingredient. What’s also unique to kojic acid is that you can also find this in soaps. However, we’d say a wash off product isn’t the most effective way to get your active ingredients.

hyperpigmentation products landscape with tranexamic azelaic and kojic acid

Plant extracts you’ll encounter: licorice root, uva ursi (bearberry), and milk thistle

Plant-based active ingredients can be a difficult mine field to navigate. It seems like many plants are touted as some form of “miracle” with very little data. This includes extracts you’ll often find in the skin brightening landscape. Here’s the chemists’ 411 on these common extracts:

  • Licorice Root Extract: This is a very popular support ingredient in skin brightening products as a secondary active. It has a long history of use and very popular reputation. Sadly, data is hard to come by for this ingredient. 
  • Uva Ursi (Bearberry) Extract: This has a reputation for skin lightening due to its natural arbutin content. Sadly, this is another one where actual clinical data is lacking. It can be a useful support ingredient, but definitely not powerful enough to use as THE star ingredient.
  • Milk Thistle Extract (Silymarin): This is a plant derived active ingredient with surprisingly great data! One of the most notable studies with silymarin tested it against hydroquinone. We have a dedicated blog post on this extract and it also happens to be one of the star ingredients in our Mr. Reliable Moisturizer.

Glycolic Acid

Yes! Chemical exfoliants are an absolute essential part of your hyperpigmentation fighting routine. We have wrote about this exfoliant extensively in our exfoliating toner guide, AHA guide, and dedicated home peel guide. So head on over to those blogs for more on how to use glycolic acid for your specific skin goals. The important thing to keep in mind is that chemical exfoliation is just ONE key aspect to tackling hyperpigmentation. Despite the sheer data around this one, remember that you should not expect this to be your single hero ingredient to do the heavy lifting despite its popularity in hyperpigmentation products. 

Vitamin C

When you’re filtering shopping sites like Sephora or Ulta by “dark spots” or “brightening”, you’ll see a lot of vitamin C serums pop up. Brightening skin and diminishing dark spots IS one of the core benefits to vitamin C. Not only can vitamin C brighten skin, its antioxidant benefits can also play a critical role in prevention. That said, it can be a difficult category to shop for. L-ascorbic acid is the form of vitamin C with the most data, but there are also a slew of vitamin C derivatives on the market to choose from. Checkout or blog posts on vitamin C science, shopping for CE Ferulic dupes, and vitamin C derivatives for more guidance.

Hydroquinone

You’ll often hear us mention that hydroquinone is the gold standard hyperpigmentation active. This is simply because of the amount of data showing hydroquinone as an effective hyperpigmentation active even in treating melasma. It’s often used as a bench in comparison to other actives as well. However, with the latest ban on the sales of OTC hydroquinone, this treatment can now only be obtained through your dermatologist. We recommend that for stubborn, severe cases of hyperpigmentation and melasma to discuss with your dermatologist to see if this is an option for you. Ultimately it is better to partner with a dermatologist to monitor your progress while using hydroquinone.

In Conclusion: Hyperpigmentation Routine Guide 101

This might be a bit overwhelming since we covered a LOT of ingredients in one blog post. You might be wondering how to put it all together. Here are a few tips to help:

  1. Prevention: Vitamin C serum and sunscreen every morning
  2. For mild pigmentation concerns and general skin brightening: Incorporate a glycolic acid home peel into our routine
  3. A More Proactive Routine: Incorporate a serum with a cocktail of ingredients (think combos with tranexamic acid + niacinamide + extracts) twice daily
  4. For very stubborn PIH or melasma: Consider retinoids and seek out a dermatologist for a hydroquinone or higher strength azelaic acid regimen

FAQ & Takeaways

What skincare actives should I look for with hyperpigmentation?

Hyperpigmentation will ultimately take a cocktail of ingredients. A good starting place will be: azelaic acid, tranexamic acid, kojic acid.

Are there botanical extracts that can help my hyperpigmentation?

Licorice root extract and uva ursi extract are the most common extracts you’ll see in treatments, however the data on their benefits is still lacking. A notable third candidate is milk thistle extract.

How long should I use a hyperpigmentation product for before I see results?

One thing you might have noticed is the majority of clinical tests we’ve referenced here are ~12 weeks. Such is the stubborn nature of hyperpigmentation! We recommend giving your regimen  at least 12 weeks of consistent use to see any noticeable difference.

*For even more info! Head on over to our hyperpigmentation shopping guide or checkout our book Skincare Decoded for more comprehensive guides on how to put together your hyperpigmentation routine. 

References

Lowe, N. J., Rizk, D., Grimes, P., Billips, M., & Pincus, S. (1998). Azelaic acid 20% cream in the treatment of facial hyperpigmentation in darker-skinned patients. Clinical therapeutics, 20(5), 945-959.

Lowe, N. J., Rizk, D., Grimes, P., Billips, M., & Pincus, S. (1998). Azelaic acid 20% cream in the treatment of facial hyperpigmentation in darker-skinned patients. Clinical therapeutics, 20(5), 945-959.

Ebrahimi, B., & Naeini, F. F. (2014). Topical tranexamic acid as a promising treatment for melasma. Journal of research in medical sciences: the official journal of Isfahan University of Medical Sciences, 19(8), 753.

J. Kim, J.‐Y. Park, T. Shibata, R. Fujiwara, H. Y. Kang, Efficacy and possible mechanisms of topical tranexamic acid in melasma, Clinical and Experimental Dermatology, Volume 41, Issue 5, 1 July 2016, Pages 480–485

Monteiro, R. C., Kishore, B. N., Bhat, R. M., Sukumar, D., Martis, J., & Ganesh, H. K. (2013). A comparative study of the efficacy of 4% hydroquinone vs 0.75% kojic acid cream in the treatment of facial melasma. Indian journal of Dermatology, 58(2), 157.

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