Astaxanthin - natural sun block

Has anyone else had experience with this? I read about it last year after both Japanese and European research found this pink chemical made you 'look better' as well as being good for your immune health and protecting against sun damage. So I put my whole family on it for a month before going on our summer holiday. Now I like to get a tan, and usually do so quite easily. However, after 3 days I had to massively decrease the amount of sun-cream I was using as I just was not tanning. Also we found we only had to put sun-block on our kids once a day. My 'healthy glow' lasted for about 4-6 weeks. I now tell all my sun sensitive patients to take astaxanthin before and during sunny hollidays.