Seaweed in shampoo started trending broadly just recently(2024-2025). I remember Bumble and Bumble having a seaweed shampoo but the ingredient itself didn't take off until scalp care started becoming more popular in these past couple of years.
What I've just learned. Seaweed with anti-tyrosinase activity is great for skin-lightening serums, but it is counterproductive in a standard shampoo because it suppresses melanin production. This can lead to unwanted hair hypopigmentation (fading hair color or premature greying) and fails to address actual hair-washing needs like cleansing or follicle stimulation.
Why Anti-Tyrosinase Seaweed Fails in Shampoo
Risk of Color Loss: Tyrosinase is the key enzyme required to produce melanin, which gives hair its natural pigment. Inhibiting this enzyme on the scalp can disrupt pigment transfer to growing hair strands.
Wasted Mechanism: Anti-tyrosinase compounds are designed to treat hyperpigmentation and dark spots on the skin. The scalp does not benefit from suppressed melanin unless treating a rare pigmentation disorder.
Rinse-Off Inefficiency: Shampoos are contact products washed down the drain within minutes, leaving active inhibitors too little time to interact meaningfully with hair follicles anyway.
Contradictory Goals: Hair care targeting vibrant color or anti-greying relies on stimulating or protecting melanogenesis, the exact opposite of what an anti-tyrosinase ingredient does.
Seaweed, like sea moss, is still great as a hair gel just not the best choice for your shampoo if you want to keep your natural pigment(not go gray). When you know better, do better. Always learning. ~salonsolids
