<prompt> tafsiri zifuatazo kutoka kwa swahili hadi kiingereza.licha ya kipindi hiki cha wakati, katika mazoezi mara nyingi hufanyika kwamba baada ya muda fulani unaweza kupunguza unilaterally au hata kumaliza upeanaji kabisa.  <response>: regrettably, from time to time, in the area of natural products, it happens that from a certain point of time, they are only available by prescription or even stop production. 