Asker: Lydia, 59 years old
Answer
A sunscreen of factor 20 or 30 will block more UV rays than a cream with factor 4 or 6, so fewer UV rays will hit the skin and your skin will tan less (as if there were less sun).
Answered by
Dr. Peter Strager
Molecular Microbiology Biomedical Sciences Medical and pharmaceutical research Molecular Biotechnology
university of Ghent
http://www.ugent.be
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