It appears in brightening formulas as Morus Alba Root Extract or Morus Alba Bark Extract, and is almost always presented with the phrase “used for centuries in traditional medicine.” The interesting part, however, is not the tradition: it is a class of molecules contained in the root but not the leaves.
With white mulberry, it is the root that matters, not the leaf. This is where the phenylflavonoids that interfere with tyrosinase are concentrated. One caveat to state upfront: the strongest evidence comes from studies on isolated enzymes and cell cultures, not from numerous clinical studies.
Article written by Elisa Avalle, founder of LeLang Skin Care and dermocosmetics specialist. Cover image generated with the support of artificial intelligence.
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What plant is it?
Morus alba is the white mulberry, the tree whose leaves feed the silkworm, cultivated for centuries in Piedmont and Lombardy for that reason. In cosmetics, it is not the leaf that is used, but the root bark, because of its prenylated polyphenol content.
The most studied compound is mulberroside, along with other phenylflavonoids. These molecules belong to the same broad family of polyphenols as rutin and the flavonoids found in many plant extracts, but have a particular affinity for the enzyme we're interested in here.
What it does
The documented activity is tyrosinase inhibition, which means slowing melanin production at the root of the process. The extract also has antioxidant activity, which is no small detail: oxidative stress is one of the stimuli that drive melanocytes to work harder, and addressing both fronts makes more sense than addressing just one. The general mechanism is covered in the guide to antioxidants.
In formulas, it is proposed mainly for age spots and overall skin tone uniformity, rather than for a single very pronounced spot.
The part not to skip
Much of the literature on this extract is in vitro: it measures how much the extract inhibits tyrosinase in a test tube, or how much pigment cultured melanocytes produce when placed in direct contact with the active ingredient.
These are real data and a necessary starting point, but they don't tell us three things: whether the molecule crosses the stratum corneum, whether it reaches the melanocytes in sufficient quantities, and whether the difference is noticeable on a person after three months. There is a barrier between the test tube and the skin, and that barrier is why many impressive results don't translate into anything.
Speaking as someone who develops formulas: that’s no reason to rule it out, but it is a reason not to base an entire product promise on it.
How to read the label
- Check which part of the plant is used. Root or Bark make sense in this context; Leaf is something else, with a different profile.
- Look at what it’s combined with. On its own, it doesn’t do much: in a serious formula, it’s paired with other tyrosinase inhibitors, such as kojic acid or alpha-arbutin, and with active ingredients that work downstream, such as niacinamide.
- Don’t expect quick results. This applies to the whole category: think in terms of months, because pigment that’s already deposited only goes away as the stratum corneum renews.
A cosmetic product does not treat any medical condition and cannot claim to do so, under Regulation (EC) No 1223/2009 and Regulation (EU) No 655/2013. Spots that appear suddenly or change in shape, color, or size should be assessed by a doctor. Anyone with a history of melasma should plan their treatment with a dermatologist.
When it makes sense
As part of a winter treatment for uneven skin tone, alongside daily sun protection, which remains non-negotiable. For the full picture, see the article on skin discoloration.
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If you’d like to find out what’s really in a brightening product you have at home, LeLang partner pharmacists can read the INCI with you.
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Frequently asked questions
What is white mulberry in cosmetics?
Morus alba is the tree whose leaves feed the silkworm, and it was also cultivated for a long time in Piedmont and Lombardy. In cosmetics, it’s not the leaf that’s used but the root bark, which is rich in prenylated polyphenols. The most studied is mulberroside, along with other phenylflavonoids that show a particular affinity for tyrosinase, the enzyme that initiates melanin production.
How does white mulberry extract work on spots?
It inhibits tyrosinase, thereby slowing melanin production at the beginning of the process. It also has antioxidant activity, which is useful because oxidative stress is one of the stimuli that prompt melanocytes to work harder. In formulas, it is mainly used for age-related spots and to even out skin tone, rather than for a single very pronounced spot.
How strong is the evidence for white mulberry?
Much of the literature is in vitro: it measures tyrosinase inhibition in a test tube or pigment production in cultured melanocytes. These are real findings and a necessary starting point, but they do not tell us whether the molecule penetrates the stratum corneum, reaches melanocytes in sufficient quantities, or produces a noticeable effect after months. So it is best considered one component of a formula, not the whole promise.
How can you identify white mulberry in the INCI?
It appears as Morus Alba Root Extract or Morus Alba Bark Extract, the names to look for when searching for ingredients that improve skin tone. Morus Alba Leaf Extract refers to the leaf, which has a different profile. The other ingredients matter too: on its own, it does little, while in a well-formulated product it works alongside kojic acid, alpha-arbutin, or niacinamide.
How long does it take to see results from white mulberry?
As with all active ingredients in this category, results are measured in months, because already-deposited pigment only fades as the stratum corneum renews. Winter is the most suitable time, always with daily sun protection. Spots that appear suddenly or change shape, color, or size should be evaluated by a doctor, and melasma treatment should be planned with a dermatologist.
Sources for this article
- Review literature on phenylflavonoids from Morus alba: in vitro tyrosinase inhibition and antioxidant activity of root extract.
- Rivas S., Pandya A.G. (2013). "Treatment of melasma with topical agents, peels and lasers: an evidence-based review". American Journal of Clinical Dermatology, vol. 14, no. 5, pp. 359-376.
- Regulation (EC) No 1223/2009 of the European Parliament and of the Council on cosmetic products.
- Commission Regulation (EU) No 655/2013, laying down common criteria for the justification of claims used in relation to cosmetic products.
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