Hi X. I received a new bottle of Biotin-PEG this Monday. When I used the DHL tracking code to check where the bottle had been during the weekend, I realised that it was shipped on Friday and had spent Saturday and Sunday at the DHL stores. The product was at room temperature when we received it. Hence, I contacted the manufacturer, company X, to tell them what happened and to ask them if it would be possible for them to send us another bottle. I told them that we could, in return, send them back the bottle that we got on Monday. However, as you can see from the emails below, they seem to be very sure that the Biotin-Peg that we recently received is perfectly OK. They say that storage at -20 degrees Celsius is necessary for long-term preservation, but not for the shipment of the product. Do we keep the bottle that we got on Monday? The bottle has been at -20 degrees Celsius since we received it. Best regards, Me.