Most villagers will visit the clinic for their annual checkup. George and Evelyn visit the clinic once per season.
Although you can enter the Clinic most days between 9am and 3pm, you cannot purchase medical supplies unless Maru or Harvey is behind the supplies counter.
Gifting medical supplies is possible, but both items are universally hated. Despite the number listed on the tooltip, no health is restored when consuming an energy tonic.
If you pass out from low health while on your horse, both you and the horse will be transported to Harvey's Clinic. Your horse will be stuck inside the Clinic until the morning when it is transported to its stable.
History
1.3.32: Red plus sign on front of building changed to blue. Interior red plus signs changed to green or desaturated.
1.4: Energy Tonic and Muscle Remedy can now be used in Tailoring.
1.6.4: Energy Tonic no longer restores health when consumed.