@willgaunitztrichologist: The answer: D) None of them, on their own. Rosemary has the most research behind it, but it’s one small study, and no oil can fix hair loss caused by low iron, thyroid issues or autoimmune conditions. Castor and coconut oil can condition your hair, but there’s no solid proof they regrow it. Find the cause first. Then an oil, diluted and patch tested, can support your scalp. What did you guess? Tell me below. #hairloss #rosemaryoil #castoroil #hairgrowth #trichology