It is quite safe, but you should still be sure to inform your acupuncturist of any medications you ate taking and whether or not you are or could be pregnant.
Some people experience no pain at all.
They are very thin. Usually 10 to 12 acupuncture needles can fit into on ordinary hypodermic needle. The needles are solid and made from stainless steel. The point of each needle is smooth. Usually there are no serious side-effects from acupuncture.