Post-inflammatory hyper-pigmentation is the accumulation of excessive melanin in the skin following pro-inflammatory events (such as intense ultraviolet light exposure, acne, or laser-induced trauma) and can occur in the under-eye area. Over there, it may provoke prominent dark circles and make you feel like a panda bear, especially if you develop melasma near that area. I have recently been in that situation. Here I tell you how tranexamic acid is helping me to move forward to a better place.
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Hi guys! Let’s discuss tranexamic acid, a trendy skin-lightening ingredient with additional anti-redness properties when topically applied to the skin.
What is tranexamic acid (TXA)?
Tranexamic acid is a synthetic analog of the amino acid lysine. It interferes with the plasminogen/plasmin enzymatic pathway, which targets and dissolves blood clots. Thus, tranexamic acid favors blood clotting.
That’s why it helps improve heavy periods in some women (when orally taken) or ease heavy bleeding upon dental surgery or childbirth.
However, decades ago, tranexamic acid also showed skin-lightening properties unexpectedly. Therefore, it has served – orally or as an injection – to tackle skin hyperpigmentation such as melasma (dark skin patches usually triggered by inflammation, hormones, and sun exposure) for over forty years.
How and why does it achieve that, even when topically applied? Be patient! I will get into that soon enough.
How did I suddenly get prominent under-eye hyperpigmentation?
If you follow my blog, you will probably know that I have struggled with rosacea and ocular rosacea. You can read the whole story in my previous article on rosacea (also learn about the different types of rosacea, if you want).
When I clarified how I managed to keep the rosacea and ocular rosacea under control by the end of that article, I commented that I went through some IPL (Intense Pulsed Light) sessions on my cheeks and near my eyes – performed by an ophthalmologist – to improve the ocular rosacea.
Months after that (at the dermatologist), I underwent two vascular laser sessions focused on the cheeks and around the eyes (but not too close to them) to get rid of some dilated blood vessels. That aimed to improve the vascular rosacea and ocular rosacea.
In hindsight, I know I would have saved myself money and trouble if I hadn’t followed through with all the IPL and vascular laser sessions that the ophthalmologist and dermatologist respectively prescribed. Now you will understand why.
The IPL helps to restore the whole cutaneous tissue (it targets more than just the blood vessels). And I believe I went through a moderate IPL approach.
However, by the end of the treatment (of several sessions), I noticed an area of skin on my left under-eye was slightly tender and painful. That feeling lasted for a while. After months, it seemed to have faded away.
Then, since the ocular rosacea (among other issues that you can read in my rosacea article) was still bothering me, I went to see a dermatologist.
She recommended performing two sessions of vascular laser (not just one) instead of IPL. The vascular laser targets only the blood vessels and, in theory, makes them shrink or collapse.
The second vascular laser session was quite aggressive: the dermatologist wanted to eliminate all the dilated vessels she could (her intention was good). From my viewpoint, it was not worth it.
It fostered inflammation, long-lasting swelling, and new dilated (visible) blood vessels right underneath the eyes and on the left cheek.
Following that second laser procedure, the tender area under my left eye reappeared (magnified), remained painful and slightly swollen (a swelling underneath the skin called angioedema), and progressively got hyper-pigmented for over a year.
And all that local inflammation also triggered melasma on my cheeks.
So that’s how I ended up like a panda bear (with a more prominent dark circle beneath the left eye).
I started to feel uncomfortable when I looked at myself in the mirror. I did not understand what went on (my under-eye got much darker during the winter).
Nor how I suddenly had melasma given that I am strict about sunscreen, I don’t get excessive sun exposure at all, and my levels of sexual hormones (that can heavily influence the appearance of melasma) are steady.
By the way, I had only experienced apparent melasma once, a few years ago, after I spent a couple of weeks at the beach most days, learning to surf. However, that melasma was gone after the summer.
I waited (for months) for the mild swelling and pain under my left eye to clear up before consulting with a dermatologist again. But they didn’t.
Therefore, at the beginning of July 2022, I saw a new dermatologist and laser specialist. He told me that the under-eye area is one of the most delicate skin areas in the body, and lasers are not always the best option.
He also put me on a combined treatment that includes topical tranexamic acid, which I will describe in detail below.
Why topical tranexamic acid? What does it do within the skin?
Plasmin: the link between the promotion of blood clotting and skin lightening
You might wonder now how the abilities of tranexamic acid to favor blood clotting relate to its skin-lightening capacity. And the thing is that the process, albeit effective, it’s not so straightforward. Let me explain that.
Fibrin, the protein that forms blood clots (together with platelets), has several consecutive residues of lysine (an amino acid).
When plasmin binds those lysines, it causes the breakdown of fibrin (and the blood clot). See the illustration below.
Tranexamic acid and lysine are very similar (tranexamic acid is an analog of lysine).
Therefore, when tranexamic acid binds plasminogen or its active form (plasmin), plasmin cannot bind fibrin and blood clots endure. See the image below.
Moreover, tranexamic acid can inhibit plasminogen activators (see the image above). So that’s the core fact: one way or another, tranexamic acid prevents plasmin activity. And that also helps ward off skin hyperpigmentation.
Then, how does tranexamic acid lighten the skin?
The thing is that plasmin does not only destroy blood clots. It also stimulates the release of pro-inflammatory molecules. Those activate melanocytes (the cells that synthesize the pigment melanin in the skin).
For example, plasmin causes the release of alpha-Melanocyte Stimulating Hormone (alpha-MSH). Alpha-MSH then binds specific receptors on the surface of melanocytes and hence causes melanin production (see the image below).
Therefore, tranexamic acid blocks all that process and thus inhibits excessive melanin production indirectly (by blocking plasmin).
Additionally, tranexamic acid may directly inhibit tyrosinase, the enzyme responsible for melanin synthesis within melanocytes.
On the other hand, plasmin favors VEGF (Vascular Endothelial Growth Factor) and other pro-angiogenic factors. These are molecules involved in new blood vessel formation (or angiogenesis) in the skin. That is a central feature of skin redness and rosacea.
Furthermore, angiogenesis may aid in triggering or worsening melasma.
Thus, tranexamic acid also appears to thwart angiogenesis and shrink blood vessels (see the image below). That’s another way to help reduce inflammation, melasma, and even rosacea.
Finally, intense exposure to sunlight (to ultraviolet and visible light) causes harm to the cellular DNA, the generation of free radicals, and the activation of inflammatory processes in the skin.
Indeed, sunlight exposure can also stimulate the plasminogen/plasmin pathway and the production of alpha-MSH and pro-angiogenic factors (such as VEGF).
Hence, tranexamic acid fends off sunlight-induced inflammation and hyperpigmentation too (see the image below).
That’s also why the consistent use of sunscreen (and a good pair of sunglasses for the eye contour area) is so effective in avoiding cutaneous hyperpigmentation.
What tranexamic acid-including treatment am I following?
As I said before, by the beginning of July, the dermatologist prescribed me a topical treatment. It included a cream with 4% tranexamic acid (you can find TXA in percentages of 2 to 5% in products from regular skincare brands).
It also contained 3% hydroquinone. That is a potent tyrosinase inhibitor and a broadly prescribed topical agent for skin hyperpigmentation.
And a low concentration of a retinoid (tretinoin) and a corticosteroid (hydrocortisone 1%).
Dermatologists use those last three ingredients together (Triple Combination Therapy) to treat melasma and post-inflammatory hyperpigmentation safely and effectively.
Tretinoin accelerates skin renewal and also helps diminish inflammation and hyperpigmentation. And corticosteroids further hinder inflammatory processes.
I started applying that treatment in July on alternative nights. I stopped it in October (when I was supposed to see the dermatologist again or discontinue the treatment). Hydroquinone can cause side effects on the skin. That’s why you should use it for no longer than a few months (usually three) at a time.
How is the tranexamic acid combination therapy working out for me?
I will share the outcomes of my tranexamic acid topical combination therapy (from July to October) for the under-eye area in the following article (the sequel to this one). So hang around with us again in two weeks. Same place and time!
Also, I will introduce you to some skincare products with tranexamic acid. They may be worth a try if you deal with postinflammatory hyperpigmentation.
What is the main insight that you took away from this article? Have you ever used TXA or hydroquinone to treat skin hyperpigmentation? Share your mind with us in the comments section below!
Additionally, please leave any questions you may have. I will answer them swiftly!
Please subscribe to the blog to stay in the know! You can also follow me on Instagram (@drmariamonterrubio) for additional tips and tricks.
See you again in two weeks! Meanwhile, do not forget to exercise your daily dose of care, beauty, and joy – because you must nourish your precious body & soul to impact the World in your unique, valuable ways.
Love,
María
For your reference:
Topical treatments for melasma and their mechanisms of action. González-Molina V et al., J Clin Aesthet Dermatol, 2022; May; 15(5): 19-28.
X-ray crystal structure of plasmin with tranexamic acid-derived active site inhibitors. Ruby H P Law et al., Blood Adv, 2017; May 9; 1(12): 766-771.
Tranexamic acid is an active site inhibitor of urokinase plasminogen activator. Wu G et al., Blood Adv, 2019; Mar 12; 3(5): 729-733.
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