The deluge of improbable health hacks on TikTok can only mean it’s the start of a new year. Here we look at some of the more curious tips and the evidence, where there is any, behind them.

Putting rubber bands around your ears to reduce facial puffiness

The South Korean fad of wrapping rubber bands around the ears for 10 minutes to reduce facial puffiness has gone global among TikTok users. Advocates claim the bands help move fluid around the lymphatic system, but there is no scientific evidence to support that. There is evidence that lymphatic massage, which uses gentle outward strokes, can reduce puffiness, but the effects are temporary.

Prof Hywel Williams, a specialist in evidence-based dermatology at the University of Nottingham, says many TikTok videos involve young, fit people with no facial puffiness to begin with. “The craze seems to be creating anxiety and inventing a new thing to worry about,” he says.

But he would like to see a proper test in which hundreds of puffy faced people wear rubber bands, a piece of cotton, or something else, and have their puffiness assessed before and after by an independent panel of aestheticians. “I am always open-minded,” he says, “and sometimes the medical profession can be wrong.”

Sticking garlic up the nose to cleanse the sinuses

Good of TikTok to provide a platform for people who want to film vast bubbles of mucus ballooning from their garlic-filled nostrils, and torrents of snot pouring out when the garlic is removed. The striking effect is portrayed as proof that garlic relieves congestion, but that is nonsense. “This is not clearing anything. The mucus was produced by the lining of the nose in response to the pungent smell of the garlic,” says Simon Gane, a consultant ear, nose and throat surgeon at University College London hospitals NHS foundation trust. “It’s not ‘released’ from anywhere. A blocked nose is usually because of swelling of the lining of the nose, not snot.”

“People should definitely not stick garlic or anything random into their nose,” says Carl Philpott, a professor of rhinology and olfactology at Norwich medical school. “For cleansing of the nose and sinuses, we recommend nasal saline irrigations using kits such as NeilMed or Sterimar, which have been shown to be beneficial in scientific studies.”

Putting castor oil in the belly button to reduce bloating

Entire theses are devoted to the importance of the navel in fashion, religion and meditation, but biologically it serves no purpose beyond reminding us we were once connected to our mother via an umbilical cord. Some TikTokers claim that pouring castor oil into the belly button, a practice known as navel oiling or navel pulling, helps digestion, reduces bloating and alleviates period pains and endometriosis.

The fad has its roots in Ayurvedic practice, an alternative medicine system. One treatment claims to involve essential oils being absorbed through the belly button, via what practitioners call the “pechoti gland”. So far, scientists have found no evidence that such a gland exists.

“Unfortunately, due to the lack of research into women’s health, combined with issues like long waiting lists and dismissal by medical professionals, many women have turned to unproven home remedies in search of relief for their symptoms,” says Dr Gemma Sharp, an epidemiologist at the University of Exeter. “There are no peer-reviewed scientific studies on applying castor oil to the skin for weight loss or to relieve endometriosis symptoms, so there’s no solid evidence of its effectiveness. In some cases, it may cause an allergic reaction, so it’s best to avoid it.”

Oatzempic helps with weight loss

Ozempic, a diabetes drug, was a runaway success last year, though it is perhaps better known for weight loss. Ozempic contains semaglutide, a hormone-mimicking compound that slows digestion. Not to be outdone, TikTokers have come up with oatzempic, a blend of oats, water and lime juice, and say it has similar effects. The claim hasn’t been tested, but people do not lose weight unless they burn more calories than they consume. Oats might help, however: they contain soluble fibre called beta-glucan, which may act to reduce body weight and body mass index.

Mouth taping

Many people breathe through the mouth rather than the nose at night, leading to a dry mouth, sore throat and bad breath. They are also prone to snoring. Taping the mouth shut with porous tape aims to redirect breathing through the nose, which has the added benefits of filtering out allergens and making inhaled air more humid. Few studies have looked at whether it works, but a pilot study of 30 people found that mouth taping reduced snoring in those with mild obstructive sleep apnoea, a disorder where breathing repeatedly stops and starts during sleep.

But mouth taping may be dangerous for some. Another trial on people with obstructive sleep apnoea found that while mouth taping typically improved airflow, more than a fifth saw it fall significantly.

“If someone knows they have no nasal obstructions, is normal weight, and does not have diagnosed moderate or severe obstructive sleep apnoea, then they can try mouth taping at home,” says Dr Andrew Huang, an otolaryngologist at Baylor College of Medicine in Houston. Those who have difficulty breathing through their nose in the day, are overweight or obese, or have diagnosed moderate-to-severe obstructive sleep apnoea, should see an otolaryngologist before trying it, he adds.