I wonder how they confirm that the "nanozyme" compound is the thing that helped here and not the presence of the needles themselves, considering microneedling i

I wonder how they confirm that the "nanozyme" compound is the thing that helped here and not the presence of the needles themselves, considering microneedling is already commonly used to stimulate hair growth, sometimes in combination with Minoxidil[0][1] [0] https://pubmed.ncbi.nlm.nih.gov/29028377/ https://pubmed.ncbi.nlm.nih.gov/29028377/ [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3746236/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3746236/