How big are those needles?

Acupuncture needles are entirely different from hypodermic needles used for shots or medication. Acupuncture needles are much thinner — each as thin as a strand of hair. They’re fine and flexible. Their points are smooth — not hollow with cutting edges like hypodermic needles. If acupuncture needles cause any sensation, it’s typically similar to a mosquito bite or a mild pinch.