Skin General cee77712 What is the best time to give oral psoralen with UVA? A Half n hour before UVA B 1 hour before UVA C Half n hour after UVA D 1 hour after UVA High-Yield Explanation Ans is'b' i.e. 1 hour before UVA Psoralens (mostly 8- MOP) is given orally 1-3 hours (average 2 hours) before exposure to UVA.