I rarely get headaches, but I have one right now after drinking some rooibos. I received a free tin from Adagio. I don't buy flavored teas, but it has some flavors added to it, so I'm wondering if that's what's causing the headache. I recall having a headache before when drinking it, not every time of course. I really don't get headaches when I don't drink tea for a few days, so I don't think it's caffeine withdrawal symptoms, and I usually only use 4.5g of tea per day anyway which isn't much caffeine. It really makes me sleepy.
I'm feeling rather itchy, mostly on my head but a bit around the body. That occurred several hours after drinking it. I would guess five or six hours. I've had that same kind of itchiness once before and right before bedtime, but I can't remember if I had that same tea that day, but it would fit the timing of me drinking it later in the afternoon. I don't drink tea in the afternoon, because it has caffeine. I've had rooibos before, red and green with no symptoms, so I'm thinking it's this particular batch.