Of all the brightening ingredients in skincare, vitamin C has the deepest research base — and sandalwood, despite centuries of traditional use across South Asia, is only in the last decade building the kind of peer-reviewed evidence vitamin C already has. Put together, they're not redundant: one is the most clinically established active available, the other brings a genuinely different, complementary mechanism.
Vitamin C: the most studied brightening ingredient there is
A systematic review of topical vitamin C specifically for melasma and photoaging found consistent evidence of real improvement in pigmentation and skin tone across the studies it covered — one of the more thoroughly reviewed brightening actives in dermatology. A separate Bayesian meta-analysis pooling 31 randomized, controlled, vehicle-compared studies found vitamin C measurably prevents UV-induced pigmentation, not just treats existing dark spots after the fact.
Mechanistically, vitamin C works two ways at once: it's an antioxidant that interferes with the pigment-production pathway, and separately, it helps counter the oxidative stress that UV exposure causes in the first place — which is part of why the prevention finding above matters, not just the treatment one.
Sandalwood: traditional ingredient, now with real clinical data behind it
Sandalwood (Santalum album) has been used in South Asian skincare for centuries, but it's only more recently been studied with the kind of controlled trials dermatology relies on. A peer-reviewed review in the Journal of Clinical and Aesthetic Dermatology found sandalwood oil has demonstrated anti-inflammatory, antimicrobial activity in controlled research — including a trial where a topical 0.5% sandalwood oil preparation reduced UVB-induced skin redness by 45% compared to placebo, and a separate 12-week trial where it reduced acne lesions by 65% compared to 25% for placebo.
A separate study focused specifically on antioxidant activity found sandalwood oil measurably scavenges reactive oxygen species — the same category of cell damage vitamin C works against, but reached through different plant chemistry, which is why the two aren't simply overlapping ingredients doing the same job twice.
Why they're combined rather than used alone
Vitamin C brings the deepest clinical evidence base specifically for pigmentation. Sandalwood brings genuine, separately-studied anti-inflammatory and antioxidant action, plus a traditional-skincare credibility that modern research is now catching up to rather than contradicting. LUBU's Radiance Bar combines Sandalwood Extract, Alpha Arbutin, Kojic Acid Dipalmitate, and Ascorbic Acid (Vitamin C) in the same soap-free, pH 5.5 base — alpha arbutin and kojic acid cover the same tyrosinase-inhibition ground discussed in our Brightening Bar guide, while vitamin C and sandalwood are what distinguish this bar's specific formulation.
The practical takeaway
- Vitamin C has one of the strongest clinical evidence bases of any brightening ingredient, for both treating and helping prevent UV-related pigmentation.
- Sandalwood is no longer just a traditional ingredient — it has its own, separate peer-reviewed evidence for anti-inflammatory and antioxidant activity on skin.
- The two work through different mechanisms, which is the actual reason for combining them rather than simply using more of one.
This is general skincare education, not a medical claim about any specific result you should expect — persistent or severe hyperpigmentation is worth discussing with a dermatologist.