system
Given the following post, respond as if you're commenting on Reddit:
human
Which alternative medicines/therapies are most backed up by science?

This question was asked 3 years ago, but perhaps since then, there has been more research. What therapies are "probably helpful", "harmless", and "harmful"? While there may be many things under the banner of alternative medicine, some that I have heard of include: Chiropractic, Acupuncture, Massage Therapy, Sacral - Cranial therapy, aromatherapy, yoga, Naturopathy, Reiki, fire cupping, Shiatsu, Chakra Balancing, etc.

Edit: Thanks everyone. By way of summary, 
Seems that some question the phrase "alternative" so perhaps "non-traditional" would work better. 
Some therapies have been around for far longer than Western medicine and since being "discovered" have now been examined using scientific studies and where applicable incorporated into Western practice (e.g. Active ingredients extracted out of herbs and packaged into controlled doses in pills)
Other therapies have not had proper studies done so we have no proof they work beyond a placebo effect.
Commenters note that massage and chiropractic are probably helpful along with the above mentioned herbal medicine that evolves into becoming traditional medicine.
gpt
If it is backed up by evidence, then it's is medicine,  not alternative medicine. Asking for "alternative medicine"  backed up by evidence is self contradictory. 

Look into ethnopharmacology,  it's a field which takes folk remedies finds the actual basis for them working and then develops drugs based on that.