Yes, you can use lactic acid and tranexamic acid together in your skincare routine. Both of these acids have their own unique properties and benefits for the skin.

Lactic acid is an alpha hydroxy acid (AHA) derived from milk. It is known for its exfoliating properties and its ability to gently remove dead skin cells, unclog pores, and improve skin texture. Lactic acid also helps to stimulate collagen production, which can lead to smoother and more youthful-looking skin.

On the other hand, tranexamic acid is not an exfoliating acid like lactic acid. It is a synthetic derivative of the amino acid lysine and is often used in skincare products for its brightening and anti-inflammatory properties. Tranexamic acid helps to reduce the production of melanin, which can help fade dark spots, hyperpigmentation, and melasma. It also has anti-inflammatory effects, which can be beneficial for those with sensitive or acne-prone skin.

When used together, lactic acid and tranexamic acid can complement each other's effects on the skin. Lactic acid can help to exfoliate and prepare the skin for better absorption of tranexamic acid, allowing it to penetrate deeper and work more effectively. Additionally, the exfoliating properties of lactic acid can help to enhance the overall brightening effects of tranexamic acid by removing the superficial layers of dead skin cells.

However, it's important to note that everyone's skin is different, and some individuals may be more sensitive to the combination of these acids. It's always a good idea to start with a patch test and introduce new products gradually into your skincare routine to monitor how your skin reacts. If you experience any irritation or discomfort, it's best to discontinue use and consult with a dermatologist.