Phitkari , or alum, has long been promoted as a simple, inexpensive home remedy for common skin concerns. Its natural astringent and antibacterial properties make it popular as a toner, aftershave and even an anti-acne hack. But despite its traditional reputation, modern dermatology raises important questions about how safe it truly is for facial skin.


In a recent video, popular dermatologist Dr. Jushya Bhatia Sarin shared how using Alum or phitkari on the face can do more harm than good. Emerging research shows that what seems harmless on the surface may have effects that most people don’t consider.


Phitkari’s salt structure
Dr. Jushya highlights that phitkari is a sulphate. is chemically a double sulphate salt, potassium aluminium sulphate, and its structure is what gives it strong astringent and desiccating properties, which means it has a strong dehydrating effect on the skin. Dr Jushya says, “Phitkari dries and stretches the skin, as it dries out water from the surface”.

Phitkari has historically been used as a styptic, i.e., a substance that helps stop minor bleeding from small cuts or shaving nicks. Its strong astringent action causes blood vessels and surface tissues to contract quickly, which is helpful for tiny wounds. Here Dr. Jushya says that phitkari was sold in ancient markets, not to use on the skin or underarms, but to reduce the amount of sweat.

This translates that alum’s traditional use for cuts doesn’t translate to safe everyday skincare.

No skin-brightening action
Another misconception Dr. Jushya addresses is the belief that alum can lighten spots, pigmentation or tan. Chemically, alum’s formula contains:

• No pigment-reducing properties
• No ability to influence melanin production
• No pathways that affect skin-brightening mechanisms

show that melanin regulation requires ingredients that work on tyrosinase or melanocyte activity, something alum cannot do. This means phitkari cannot fade dark spots, treat hyperpigmentation, or provide any brightening effect, despite widespread social media claims.


Another thing Dr. Jushya highlights is that physical scrubs, especially those using hard, jagged or coarse particles, can cause microscopic tears or “micro-cuts” in the outermost layer of skin. In controlled studies, repeated rubbing or mechanical abrasion has been shown to damage the skin barrier: an in-vitro study found that mechanical rubbing markedly reduced barrier function, increasing skin permeability to water and other substances.


When the barrier is compromised like this, the skin becomes more vulnerable to environmental irritants, UV radiation, and infections, all factors that can trigger inflammation or stress responses. These, in turn, may stimulate pigment-producing cells (melanocytes), leading to post-inflammatory hyperpigmentation (PIH), particularly in medium-to-dark skin types.


In short: using harsh scrubs, or rubbing vigorously, can cause tiny skin injuries that weaken the skin’s natural protection. As the skin tries to heal from these repeated micro-traumas, pigment changes (dark spots), sensitivity, dryness or even acne may follow, precisely the opposite of the “glow up” many scrubs promise.