Hanoi is the one city here with a real winter. At the Láng station the average daily high is 20.2°C in January and 34.9°C in June, and the record is 42.8°C, set in May (Wikipedia, Hanoi climate table).
A Hanoi parcel spends 1 to 3 days on the road from Ho Chi Minh City, the longest leg in this guide. Peptara Labs says freeze-dried vials keep at room temperature for weeks, so even the long leg sits inside that by its own account. From May to August, the risk is the wait at the end: a box in a parked car or at a sunny gate.
So keep your tracking number handy and be in on the day. Distance changes the delivery question, not the paperwork: read the published lot certificate, compare the ways to buy, and see storing peptides in Vietnam heat.
Sources: Wikipedia, Hanoi climate (World Meteorological Organization and Vietnam Institute for Building Science and Technology data); peptaralabs.io/vietnam, read 3 October 2026