A 30 percent increase in online purchases of energy supplements in May is widely seen as a response to students' rising stress levels ahead of university entrance exams this month.
According to the Convert Group's eRetail Audit service, the most sought-after products were energy supplements containing fish oil.
A facility for the production of Spirulina through processing algal biomass is being built near Bulgaria's southern city of Pazardzhik.
In 3-4 months the company is to start producing the dietary supplement made from blue-green algae there.
The food supplement is used a source of protein and other nutrients.