If you’ve researched dark spots or melasma, you’ve met these three names — usually with a lot of confident, contradictory advice attached. They’re all “tyrosinase inhibitors,” meaning they all work by dialling down the same enzyme that switches on melanin. But they differ a lot in strength, safety and how you should (or shouldn’t) get hold of them. Here’s a straight comparison to help you choose well.
The common thread
Melanin is made when the enzyme tyrosinase converts an amino acid into pigment. Arbutin, hydroquinone and kojic acid all interfere with that step — they just do it with different potency and different trade-offs. None of them is a substitute for sun protection; all of them work better with it, and some barely work without it.
Hydroquinone: potent, but now a prescription medicine
Hydroquinone has long been regarded as the most effective topical lightening agent — the benchmark others are measured against. But its status has changed significantly, and this is the part to understand before you buy anything online.
In the United States, the sale of over-the-counter hydroquinone was effectively ended by the 2020 CARES Act; there is now no FDA-approved over-the-counter skin-lightening drug, and hydroquinone requires a prescription (U.S. FDA, 2022). The European Union likewise prohibits it in over-the-counter cosmetics, permitting it only in pharmaceutical formulations. The reason is safety: the FDA has received reports of serious effects including rashes, facial swelling, and exogenous ochronosis — a bluish-black discolouration that can be permanent and, cruelly, is a worsening of the very pigmentation people were treating (U.S. FDA, 2022; Journal of the American Academy of Dermatology). Ochronosis is linked to prolonged and unsupervised use, and it disproportionately affects people with skin of colour.
None of this means hydroquinone is useless — under a dermatologist’s supervision, for defined courses, it remains a valuable tool. It means it’s a doctor’s tool, not a shelf purchase. In India too, hydroquinone is a prescription medicine. If a cream promises dramatic lightening and you’re not sure what’s in it, that’s a reason for caution, not excitement — unregulated imported “fairness” creams have been found to contain high, undisclosed levels of hydroquinone (and sometimes mercury or steroids).
Alpha arbutin: the gentle, everyday option
Alpha arbutin is, in effect, a gentler, more stable cousin of hydroquinone — it’s a naturally derived compound that reversibly inhibits tyrosinase, releasing its active slowly. It’s been used for pigmentation since the late 1980s and has reduced melasma severity scores in trials, though it’s milder and slower than hydroquinone (review in PMC, 2024). Its big advantage is tolerability: it’s suitable for over-the-counter use and everyday routines, with only occasional mild irritation reported. For most people managing everyday dark spots and uneven tone at home, arbutin is a sensible, low-risk starting point.
Kojic acid: effective, but can sensitise
Kojic acid, derived from fungi, has been a skin-lightening ingredient since the late 1980s and works both by inhibiting tyrosinase and as an antioxidant (review in PMC, 2024). It’s a popular over-the-counter option and can be effective, but it’s more prone to causing irritation and contact sensitivity than arbutin, particularly at higher strengths or with prolonged use. It’s often found combined with other brighteners. A good middle option — a little stronger than arbutin, a little more likely to irritate.
A quick way to choose
- Want a low-risk daily brightener you can buy yourself? Start with alpha arbutin (or gentle all-rounders like niacinamide, vitamin C or azelaic acid).
- Comfortable with something a bit stronger and willing to watch for irritation? Kojic acid, ideally patch-tested first.
- Dealing with stubborn melasma or significant pigmentation? See a dermatologist about prescription options — supervised hydroquinone, or tranexamic acid — rather than escalating on your own.
Whichever you choose, the rules from our hyperpigmentation guide still apply: sun protection first, one active at a time, protect the barrier (irritated skin pigments more), and be patient over months. And remember the Indian-climate reality — heat and strong sun make pigmentation relapse-prone, which is the whole reason we think about actives in the context of the environment they’re used in.
We’re developing pH Matter’s pigmentation range around gentle, effective, well-tolerated actives suited to Indian skin and conditions. If you’d like a note when they’re ready, leave your email — no spam, just the science as it comes.
FAQ
Which is better: alpha arbutin, hydroquinone or kojic acid?
It depends on your needs. Hydroquinone is the most potent but is now a prescription medicine due to safety concerns. Alpha arbutin is the gentlest and best for everyday over-the-counter use. Kojic acid is effective but more likely to irritate. For stubborn pigmentation, see a dermatologist.
Why is hydroquinone prescription-only now?
Because of safety reports including rashes, facial swelling, and exogenous ochronosis (a possibly permanent darkening), especially with prolonged, unsupervised use. The US ended OTC sales in 2020 and the EU restricts it to pharmaceutical use; in India it’s a prescription medicine.
Is alpha arbutin safe for daily use?
Generally yes — it’s a gentler, slow-release relative of hydroquinone, suitable for over-the-counter everyday use, with only occasional mild irritation. Pair it with daily sun protection for results.
Can kojic acid irritate the skin?
It can, more so than arbutin, particularly at higher concentrations or with prolonged use, and it may cause contact sensitivity. Patch-test first and introduce it gradually.
Are “fairness creams” with fast results safe?
Be cautious. Unregulated creams promising dramatic lightening have been found to contain high, undisclosed levels of hydroquinone, and sometimes mercury or steroids, which can seriously harm skin. Choose known ingredients, and see a dermatologist for strong treatments.
Written by the pH Matter Editorial team. Educational only, and not a substitute for a dermatologist’s advice. Hydroquinone is a prescription medicine and should be used only under medical supervision.