Prepare
The GR20 first-aid kit
On the GR20, the ideal first-aid kit fits in a pouch weighing a few hundred grams. It handles the trail's real everyday injuries — blisters, small cuts, sunburn — and nothing more. Here is what to pack, what to leave at home, and how to deal with the most common problems.
The philosophy
Light, built for minor injuries
The principle is simple: a GR20 first-aid kit should be light. It exists to patch up minor trail injuries — blisters, scrapes, sunburn — so you can walk again the next day. For anything beyond that, the right answer is not in your pack: it is 112 (or 114 by text) and the refuge wardens, who know the terrain and how to alert mountain rescue. Phone coverage is missing along much of the route — our safety page covers this. One last pillar: before leaving, discuss your kit with your doctor or pharmacist, who will adapt it to your personal situation. This page only lists generic equipment.
The contents
The essentials
- Second-skin blister plasters — the heart of the kit, kept within easy reach during the day
- A small bottle of antiseptic and sterile compresses for cleaning cuts and scrapes on the granite
- Adhesive tape and strapping tape: protect a hot spot, support a joint that starts complaining
- Tweezers, for splinters and ticks
- High-SPF sunscreen and SPF lip balm — carried within reach, not buried in the pack
- Oral rehydration salts for the hottest days
- An emergency blanket: a few grams that matter if someone has to wait for rescue
- A whistle (often built into the backpack) to signal your position
- Any personal treatments of your own, prepared with your doctor or pharmacist
On the trail
The GR20's three classic ailments
Blisters
Blisters are the number-one cause of GR20 dropouts, and the most avoidable one. The rule fits in one sentence: as soon as a spot starts to heat up, stop and protect it — do not wait for the refuge. The full method — preparing your feet before departure, reacting on the trail, treating in the evening — is detailed on our feet and blisters page.
Knees
The GR20's descents are long and punishing, and knees feel it fast. The best protection weighs nothing in the kit: trekking poles to absorb impact, short steps, and a reasonable pace over the first days. Strapping tape can support a joint that starts to complain; if pain sets in, shorten the stage rather than push through.
Sun and water
At altitude, the Corsican sun hits hard, even through haze. High-SPF sunscreen reapplied during the day, a cap and sunglasses do most of the work. As for water, drink regularly without waiting to feel thirsty: dehydration is a real risk on long, exposed stages. Rehydration salts earn their place in the kit for the hottest days.
Leave behind
The dead weight
- The complete family medicine cabinet: a kit you never open still weighs on every col
- "Just in case" duplicates: one antiseptic and one roll of tape are enough
- Heavy treatment gear (splints, full kits…): that level of problem is a job for mountain rescue, not your pack
- Products you have never tested before departure: if you don't know how to use it, it won't help
If you have any doubts about your health or your treatments, talk to your doctor or pharmacist before departure — this page gives no medical advice.