There is not one answer to that question because there are a number of factors at play! Below are the three most important areas.
First, there is ‘you’. The complexity and nature of your complaint, your age, your medical history, your present physical condition, and any past traumas. Imagine two sprinters about to race the 100-meter hurdles. The application of acupuncture is like removing hurdles, but one racer is a very fit carpenter in her 20’s and the other is a retired and overweight 80-year-old. Who is likely to finish first?
Secondly, there is ‘treatment density’; this is how long you wait between appointments. Generally speaking, a series of two treatments two times per week for 2-5 weeks is necessary. Then, depending on how you are doing, you can decrease to once per week, then once every other week until you are better. If you can only make it into the clinic once per week, that is ‘okay’, but clients that come in twice per week recover much quicker.
Occasionally, someone says, “I tried acupuncture once and it didn’t work”. The problem is “once”. It’s like saying, “I tried taking a vitamin once and it didn’t fix me”. Acupuncture works by helping your body heal itself; it does this by opening pathways of communications that are closed - sometimes that’s a REALLY big hurdle. Or, sometimes, not enough hurdles are removed for immediate relief. It’s important to give the treatments an opportunity to work by actually getting treatments.
Thirdly is the factor of what you are doing or not doing to help yourself. Acupuncture can almost always help someone recover from injury or illness, but if a client continues to expose her/himself to something that is causing harm, then treatment effect will only be temporary.
To sum up: best case scenario usually means a minimum of four treatments (occasionally less); a complex or longer standing scenario may mean a minimum of ten treatments (sometimes more).
Lastly, some people like to get treatments for general relaxation or maintenance. In that case, once per month is helpful.