There are a number of factors to consider when answering this question including the nature of the condition as well as how deep or longstanding it is.
Most people have a treatment weekly until a noticeable improvement is made, when treatments will be gradually spaced over longer periods.
Often a noticeable improvement is made within 3-5 treatments. Some conditions, such as those related to periods or fertility require longer to see results. Some musculo-skeletal conditions can improve greatly with 1 or 2 treatments.
Remember acupuncturists treat the person not the condition, so each persons’ needs and treatment plan will be different.