Martin Huang's administration of sheep foetal cells for rejuvenation, is technically classified as a form of xenotransplantation.
Other types of xenotransplants would be - sticking an animal (e.g.pig) organ (heart, liver, kidney etc) into a human recipient, or putting animal (again usually pig) cells into people (e.g. pancreatic islet cells).
Strangely xenotransplants seem to be a relatively unregulated medical procedure. The HSA regulates medicines, complementary medicines, cosmetics and medical devices but apparently not animal cells. It would seem that xenotransplants would be regulated under transplantation laws, but not so. The Human Organ Transplant Act doesn't cover animal cells into humans, just the use of human organs.
So doctors seems to be pretty unregulated with respect to their sticking animal bits and pieces into people. Possibly it may be considered an experimental surgical technique, but one could argue that sticking sheep fetal cells into someone isn't really surgery. It could possibly be regarded as an experimental procedure or a clinical trial; in which case it should be approved by the ethics committee. But this would assume the doctor would classify it as an experiment. If he maintains that the procedure is not experimental he need not subject it to ethics review.
It then becomes the responsibility of the Singapore Medical Council to consider it under Para 4.1.4 of the ethical guidelines. Unproven therapies. And that seems to be pretty inconsistently interpreted at the moment.
It would seem that Singapore is quite backward and confused where this is concerned.
Here is a list of site where you can read about regulations elsewhere:
6 years ago