have a couple of question on sun tanning.

i read on skinbiology website that the best duration under the sun is 20-30mins. so normally during sun tanning, i will each tan 15-20mins for front and back of my body(total 30-40mins per session) about 2-4time per week. i am not using any sunblock at the moment until i find a suitable one. hopefully soon. my questions is:

1) will the skin need longer and longer tanning duration to get dark as it progress? as i not using any sunblock lotion, i don't want to stay too long under the sun.

2) let say i am using a SPF30 sun screen. will this require me to tan longer to get the effect without sun screen?

currently i am either using olive oil or CP serum after tanning for recovery. thanks for the time.

Your skin will produce more melanin after about three days. In a few weeks, it will also thicken and be more protective.

But the key is to tan slowly. The skin's protective antioxidant systems hold up about 45 minutes in direct sunlight then the UV rays begin to damage the skin. So using a UV blocker to slow the tanning, will cause much less damage.