Both are top-tier and CDC-endorsed - concentration matters more than the molecule: DEET is the 70-year reference with the longest protection per application (20 to 30% for 4 to 6-plus hours) and the widest pest range; picaridin matches it at equal concentration while being odorless, dry-feeling, and safe for plastics and gear.
DEET's costs: smell, grease, and it dissolves plastics. Decision rule: maximum-duration protection in high-disease regions = 20 to 30% DEET; everyday, gear-safe, kid-tolerated use = 20% picaridin. Both safe per label, including in pregnancy. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper .
What to do
Common questions
DEET vs picaridin: which repellent?
Both are top-tier, EPA-registered, and CDC-endorsed - the honest answer is that concentration matters more than the molecule, and the choice comes down to feel and use case. DEET is the 70-year reference standard: decades of field evidence, the longest protection per application (20 to 30% covers 4 to 6-plus hours), and proven against the widest range of biters including ticks. Its costs are sensory and material: the smell, the greasy feel, and it dissolves plastics - watch faces, sunglasses, phone cases, and synthetic fabrics can take damage. Picaridin is the newer challenger: studies matching it against DEET at equal concentration show comparable mosquito protection, it is nearly odorless, feels dry, and it will not melt your gear - the trade-off is a shorter track record and typically needing reapplication a bit sooner at lower concentrations. The decision rule: for maximum-duration single-application protection (long hikes, high-disease regions), 20 to 30% DEET; for everyday, face-adjacent, gear-safe, child-tolerated use, 20% picaridin. Both beat every botanical and every wearable by a wide margin, and both are safe used per label, including in pregnancy, per the CDC.