If your lab is going through research peptides like they're going out of style, you of course have to keep ordering them over and over. Ordering extra is a good idea, but you have to be sure that the extra peptides won't expire, for lack of a better word. So you don't want to order too many because that would just be a waste, but you don't want to order too few because then you're stuck with more paperwork as you order more. Look at these three conditions to better narrow down how many extra peptides to order.
Short Shelf Life
Peptides have a short shelf life, so you can't order more than you'll use before they expire. Take a look at just how quickly you're using them: compare when you received them, when you used them, and what the expiration dates are on the peptides. That will give you an idea of how much time you have to play with. If you're constantly finishing up a supply of peptides just before it expires, then you can't really order a lot of extra peptides, if any. If there are weeks or months, though, then you might be able to order enough extra to cover a couple more weeks or months. Do ensure you have room to store the extra peptides once you receive them.
Transit Time and Storage Conditions
Other issues to look at include the transit time and the conditions in which the peptides are stored. If they're stored in less-than-optimal conditions, for whatever reason, that can make their shelf lives even shorter. Long transit times between ordering and receiving the peptides also influence how long you'll have to use them. If there's a weather system coming into the region that could delay delivery, for example, wait until after the system has passed through so that the peptides don't languish in a delivery warehouse for days.
You also have to take a look at future research needs. If your research is funded by a private grant, for example, that grant can be severely cut at any time. That would reduce your need for peptides, certainly, and you wouldn't want to spend the money on extra peptides if you didn't think your grant was secure. On the other hand, you could be planning to expand soon, in which case ordering a supply of extra peptides could be very helpful.
Getting extra peptides is easy, but you want to be sure you'll actually use them. You may want to call your supplier to see if there are larger amounts of peptides available (almost like bulk ordering) to cut costs while still providing you with extra, thus cutting down the number of times you have to order them. To learn more, contact a company like Maxim Peptide.