I’ve flown through Heathrow and other BAA Airports several times since the new restrictions and it is honestly not as bad as the information you can find online may lead you to believe. I’ve gone through with less hassle than my travelling companions who were not carrying potentially dubious items!
In all the amount of time I’ve spent standing in security queues watching others go through, I’ve never actually seen anyone be asked to test a liquid (may relate to the science behind the regulation being dubious in the extreme!) Things like insulin and glucagon, though, are anyway very, very unlikely to be questioned. The security staff at Heathrow are well trained and generally know what this stuff is. If you meet someone obstructive, politely ask for a supervisor. Keeping the labels on the boxes - including for the penfill - is useful (it is required by US security). Keeping the caps on unused bottles also verifies that they haven’t been tampered with.
You must remember that all liquids need to be in quantities less than 100ml and placed in a resealable plastic bag not larger than 20cmx20cm - 1 bag per passenger. They provide these free of charge at the entrance to the screening area. Technically you are not required to place medications in the plastic bag and are allowed a separate plastic bag, but in practice, unless you have huge quantities it is probably easier to do so. I’ve managed to get four boxed vials of Humalog, plus a back-up vial of NPH, 3 glucagon kits and emergency hydrocortisone kits, plus contact lenses into said bag. To save space you can put things in not in their box, but keep the boxes and labels with you as well. As for sharps, you are allowed to carry what is necessary for your trip - not just the journey. So you can carry what you need for the entire time away and I’ve certainly never had a problem doing so. Don’t draw attention to your sharps. Pack them together in another plastic bag or toiletry case inside your carry-on bag, so they can removed easily if security do want to inspect them, but don’t take this bag out of the carry-on bag or mention the sharps. Just put the bag through the x-ray and see what happens.
The biggest problem you may encounter is fitting all your supplies in a carry-on bag the prescribed size. Again, technically you are allowed a second bag for essential medical items. You will require the clearance of your airline and a letter from them stating that they have approved this before security will let you through with more than one carry-on bag. (Some transfer passengers, as you will be, are not subject to the one bag rule, so check carefully with the airline.)
Pumps are usually well recognised at airport security here. I’ve learned though that it is best to have it in a visible spot. I once forgot to remove mine from my bra and they would not allow me to remove it there and then, but insisted on taking me to a private room for a proper inspection! I now have it on my waistband. When they give you the “remove your cell phone” line just say it is a medical device. If you meet a security screener who doubts that, just ask for a supervisor.
The regulations are meant to sound awful. The idea is to scare people a little. The bottom line though is that who you are/what you look like is more likely to have an effect on whether you get stopped than what you are carrying.
Hope you have a safe trip, without security headaches.