Ask a massage therapist how often you should have a massage and you have asked a person with an interest in the answer. So here is a version written with that acknowledged up front.
The honest answer is that it depends on why you are coming, and for most people the right frequency is less often than a studio would like and more often than they currently manage.
What actually determines it
Three things, in order.
What you are trying to achieve. Maintaining general wellbeing is a different problem from resolving a specific persistent issue, and they warrant different spacing.
What you are doing between sessions. Someone who moves, stretches and sleeps reasonably holds the benefit far longer than someone who returns straight to eight hours at a desk. This factor is bigger than most people credit.
What you can sustain. A schedule you abandon in six weeks is worth less than a modest one you keep for two years. Be realistic rather than aspirational.
Rough guidance by reason
General wellbeing and stress. Once a month is the sensible default. Frequent enough to be a rhythm rather than an event, infrequent enough to be affordable indefinitely. Every six to eight weeks also works.
A specific problem — a knotted shoulder, a stiff hip. Weekly or fortnightly for a short block of three to six sessions, then reassess and space out. Resolving something is a course of work, not a single appointment, and one deep tissue session on a six-month-old problem will help for three days.
Regular training or physical work. Every two to three weeks during heavy periods. Athletes go more often; most people are not athletes.
Desk work and general stiffness. Every three to four weeks, ideally alongside something you do yourself. The massage manages what accumulates; it does not stop it accumulating.
Chronic pain, under medical supervision. Whatever your doctor or physiotherapist advises. Often weekly at first.
Occasional treat. Whenever you like. This is a completely legitimate reason and needs no schedule.
The thing studios are quiet about
Frequency is not the main variable. What you do between sessions is.
A monthly massage plus five minutes of daily movement will leave you in better shape than a weekly massage and nothing else. The hour on the table releases what has built up; how fast it builds again is determined by the other 719 hours.
This is inconvenient to say if you sell massages, and it is true.
Can you have too many?
For most healthy people, weekly is fine and there is no cumulative harm. Twice-weekly deep tissue on the same area is more than most tissue wants — soreness that does not clear between sessions is the sign to space out.
The more common excess is financial rather than physical. Massage is a real cost, and a schedule that quietly becomes a strain has stopped being good for your wellbeing whatever it is doing for your shoulders.
If you can only go occasionally
Which is most people. Three ways to get more from it.
Pick your moment. Not a random Tuesday. Before or after a period you know will be demanding, or at the point in a season when your body always struggles. A well-timed session does more than a randomly timed one.
Be specific about what you want. "The right side of my neck, it has been wrong for a month, I sit at a desk" gets you a better hour than "just relaxing please". Vagueness costs you the first fifteen minutes.
Extend it afterwards. Do not go straight back to what caused the problem. Ask the therapist for two stretches for the area they worked on — every good therapist has an answer and almost nobody asks. Those two stretches, done daily, are what makes a single massage last a month instead of three days.
Packages
Most studios sell blocks at a discount. They are worth it under two conditions: the per-session price is genuinely better, and you would realistically have booked those sessions anyway.
Buying ten sessions to save fifteen per cent and using four of them is not a saving. Check expiry dates, and check whether they transfer to another treatment or another person if your circumstances change.
A reasonable plan for most people
If you want a default and do not want to think about it:
Once a month, same treatment, same therapist, plus five minutes of daily movement for whatever your problem area is. If something specific flares, temporarily go to fortnightly for three sessions, then return to monthly.
Same therapist matters more than people expect. Someone who has worked on you six times knows your body, remembers the left shoulder, and spends the hour working rather than exploring.
One thing you can do today
Think back to your last massage. How long did the benefit last — three days, a week, a month?
That number is your actual interval, and it is more informative than any general recommendation. If it was three days, the answer is not more massages; it is finding out what is undoing them so quickly.