No foreign-trained doctors applying to work here will be allowed to offer aesthetic treatments while they are on conditional registration, and no more than 20 per cent of their time can be spent on health screening.
The new rules under the Singapore Medical Council (SMC) Registration and Supervisory Framework were issued on Dec 18 and are now in effect.
All foreign-trained doctors must spend at least two years under conditional registration, during which they need to work under supervision, before they can be considered for full registration that allows them to practise on their own.
There were 256 new conditionally registered doctors in 2016, bringing the total to 2,250 as of the end of 2016, with only 146 working in the private sector.
An SMC spokesman told The Straits Times that the compulsory supervisory period, which ranges from two to four years, is to ensure that these doctors are able to provide conventional medical care, which is "treating illnesses and the sick".
Aesthetic treatments do not deal with medical problems, while health screening does not give doctors practice in treating illnesses.
Working in largely health screening and aesthetics will not be recognised as "supervised practice", the spokesman said.
"So they should not be allowed in such settings."
She added that only a few conditionally registered doctors devote all their time to providing aesthetic treatments, which pay well, or to health screening services.
Doctors working here on conditional registration, who are already offering aesthetic treatments or who spend most of their time on health screening, may continue to do so.
But the time spent on such activities from today will not be taken into account for their application for full registration.
If they change employers or the place of practice, they will no longer be allowed to do aesthetic work or spend more than 20 per cent of their time on health screening.
Even if they do not, the spokesman said the SMC "will be considering their position in the light of aesthetic practice being no longer acceptable for full registration. They will be informed of SMC's position for their current C-registration".
The new rules also do not allow conditionally registered doctors to move to private practice until they have reached level 3 of supervision.
The SMC says "most doctors need at least close to two years to reach level 3".
At that level, a conditionally registered doctor is allowed more autonomy and does not need to be as closely supervised.
Previously, they could move to private practice after one year in the public sector if they had moved up to level 2 of supervision.
The change does not affect those who were already working in the private sector on Dec 18, when the new rule became effective.
Parkway and the Singapore Medical Group, which both provide health screening, said they are not affected as their doctors are all on full registration.
Only Aesthetics, which has seven clinics, said it has two doctors on conditional registration providing aesthetic treatments.
Ms Nicole Chia, a marketing executive at Only Aesthetics, said the two doctors will continue in this role.