If you are worried about smell loss due to Covid-19, ditch steroids and try sniffing at least four different odours twice a day, suggest an international group of smell experts.The team, including Prof Carl Philpott from the University of East Anglia in the UK, noted that steroids should not be used to treat smell loss caused by Covid-19. Instead, 'smell training' -- a process that involves sniffing at least four different odours twice a day for several months, they recommend in the paper detailed in the International Forum of Allergy and Rhinology.Smell loss is a prominent symptom of Covid-19, and the pandemic is leaving many people with long-term smell loss.Corticosteroids -- a class of drug that lowers inflammation in the body -- are often prescribed to help treat conditions such as asthma, and they have been considered as a therapeutic option for smell loss caused by Covid-19."But they have well-known potential side effects including fluid retention, high blood pressure, and problems with mood swings and behaviour," Carl Philpott, Professor and smell loss expert from UEA's Norwich Medical School."The huge rise in smell loss caused by Covid-19 has created an unprecedented worldwide demand for treatment. Around one in five people who experience smell loss as a result of Covid-19 report that their sense of smell has not returned to normal eight weeks after falling ill," Philpott added.But research shows that 90 per cent of people will have fully recovered their sense of smell after six months.The team carried out a systematic evidence-based review to see whether corticosteroids could help people regain their sense of smell.They found very little evidence that corticosteroids will help with smell loss. And because they have well known potential adverse side effects, they advise against its use as a treatment for post-viral smell loss.But smell training, on the other hand, could be helpful. "It aims to help recovery based on neuroplasticity -- the brain's ability to reorganise itself to compensate for a change or injury," Philpott said.