No milk and sweetener should be added to the teas (scroll down), if you want to derive 100% health benefits. But of course, there is an exception. You can add 1/2 tsp sugar (if you have sweet tooth) in your cup of Darjeeling Black Supreme Tea.
Caffeine-in-traces is found in Darjeeling Oolong Classic Tea, Darjeeling Silver Needle White Tea, Immune+, Nutrition+, Refresh+ and Slim+. These teas are best early morning, mid-morning (around 10.30-11 am) and mid-evening (around 4.30-5 pm).
There is no caffeine in Himalayan Tulsi-Rhododendron and Himalayan Spices Tea. These are purely herbal and can be drunk any time.
3 teas (Darjeeling Black Supreme Tea, Darjeeling Green Classic Tea and Maofeng Chinese Green Tea) and 2 teas with herbal blends (Rose Black Tea and Ginger Lemon Tea) have little caffeine. Refrain yourself from drinking these 5 teas after 6 pm. It may disrupt your sleep.
All are 'WHOLE LEAF TEAS'; meaning, the tea leaves are whole, and not in broken or dust form.