According to New Scientist, some popular “black” hair products contain female hormones:
Unbeknown to many parents, a few hair products — especially some marketed to black people — contain small amounts of hormones that could cause premature sexual development in girls.
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Throughout the West, girls are tending to reach puberty earlier. This has been blamed on everything from improved diet to environmental contaminants. But African-American girls are developing even earlier than their white counterparts. About half of black girls in the US begin developing breasts or pubic hair by age eight, compared with just 15 per cent of white girls, one study has found. In Africa, girls enter puberty much later, regardless of their socioeconomic status.
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The products are sold as shampoos or treatments to deep-condition dry, brittle hair. The labels usually state that they contain placenta, hormones or “estrogen”, although not all products that make such claims contain active hormones.