What is oil pulling?
Oil pulling is an ancient oral health practice from the ayurvedic tradition that claims to improve oral health by removing bacteria and other toxins. The method consists of swishing a tablespoon full of oil (usually coconut or sesame) around the mouth for 15-20 minutes. It is recommended to oil pull in the morning on an empty stomach before cleaning with fingers or a toothbrush. After swishing for 15-20 minutes, the oil should be spat out to avoid swallowing the bacteria.
Recent resurgence and proposed benefits
Oil pulling has become a favorite topic of many wellness blogs and forums, citing benefits such as whiter teeth, improved gum health, clearer skin, and improvements in arthritis, migraines, hormone imbalances, skin conditions, and more.
How does it work?
Most oral diseases stem from an overgrowth of certain bacteria in our mouths. Some of these species produce acid that erodes the enamel in our teeth and causes cavities or tooth loss. Others cause damage to our gums and cause inflammation that leads to gum disease like gingivitis or periodontitis (read more: What is your oral microbiome?).
Oil pulling claims to activate certain enzymes (proteins) in our saliva, which remove "chemical toxins, bacteria toxins, and environmental toxins" . Certain oils have differing antimicrobial properties, such as lauric acid in Coconut oil, which reduce bacteria adhesion and accumulation in the mouth.
It is good to be skeptical about practices that promise such wide-ranging benefits, so we looked into the scientific literature to see if we could find any studies to back up the claims.
One 2008 study by Asokan et al. compared the effectiveness of a 10-minute oil pulling in removing S. Mutans, one of the bacteria responsible for cavities, against a 30-second rinse with chlorhexidine mouthwash. The study found that the chlorhexidine wash showed a significant reduction in S. Mutans in all-time points measured (24hr, 48hr, 1 week, 2 weeks), while oil pulling showed reduction after 1 to 2 weeks .
Another study by Asokan in 2011 ran a trial of 10 adolescents comparing oil pulling and a chlorhexidine wash for halitosis (bad breath) and found "oil pulling therapy has been equally effective like chlorhexidine on halitosis and organisms, associated with halitosis." .
A more recent study by Gbinigie, et al. in 2015 reviewed randomized controlled trials (RCTs) to measure the effectiveness of oil pulling on dental hygiene and found that "at present, there isn't enough information about the benefits and potential harms of oil pulling to help us decide whether or not we should take on daily oil pulling, in addition to tooth brushing." They concluded that "future clinical trials should be more rigorous and better reported" .
This conclusion was supported by a study review in 2017 by Mythri, who analyzed 21 published studies and found that only 6 had a proper study design. Reasons for rejecting the other 15 included misinterpretation of results from a small sample size.
From this, they concluded that based on a lack of evidence, oil pulling cannot be recommended to replace the standard oral hygiene regimen (brushing and flossing) but that it can be an effective supplemental aid.
Drawbacks and harmful side effects
Oil pulling is largely considered safe but can cause a sore jaw or headache from the rigorous, extended action of swishing the oil. If the oil is swallowed, it may lead to an upset stomach or diarrhea. There is also a possible tie to Lipid Pneumonia, which is caused when excess fat particles enter the lungs.
There is no evidence to suggest that oil pulling should replace the recommended hygiene regimen of brushing your teeth twice a day and flossing. Oil pulling may supplement a proper oral hygiene routine by removing food remnants that can be broken down with fat (fat-soluble), but most supportive claims are anecdotal to date. 
If done correctly, brushing and flossing have shown to be more effective in removing disease-causing bacteria and preventing cavities and gum disease. Brushing and flossing should not be painful and get easier after a short time. You can find our guide on how to properly brush and floss here.