TIANJIN, July 11 (Xinhua) -- Customs officers in north China's Tianjin Municipality seized 1,550 human placental extract injections this year, the customs said Thursday.

The injections, totaling 3,100 milliliters, were found by the customs officers in postal packages and personal luggage.

Human placental extract injections are biological products, which need special quarantine certificates and approval when entering or exiting the country, according to the customs.

Human placental extract has become popular in recent years in China, as it has been claimed to boost immunity and improve one's looks.

Many consumers have been found illegal ways to purchase human placental extract injections, however, those that have not been quarantined might carry pathogens including hepatitis or HIV, posing a risk to consumers.