Was the plant just moved, shipped or otherwise shocked?
Generally, houseplants don’t like change. They can be cranky for a few days or even a few weeks after they arrive at your home, or after a move to a new location within your home. Give your Pilea
some time and it will likely recover by itself if all other care requirements are being met.
Did you forget to water?
If your Pilea hasn’t been moved or shocked, it might be thirsty. Plants generally lose leaf stiffness when they need water. Check your Pilea’s soil and if it seems overly dry, give the plant a good sip. Also, it might be a good idea to aerate the plant’s soil using a toothpick or chopstick if it’s been a while since you last watered. If the soil is too dry or compacted, water might be channeling and not reaching the roots properly.
Are you overwatering?
Yes, drooping can be caused by both too much and too little water. If your Pilea seems droopy and hasn’t been moved nor underwatered, try having a look at its soil and roots. Does the soil seem overly wet? If so, cut back on watering and see if your Pilea perks up after a few days. If your Pilea is still looking sad after a week or so, root rot could be occurring.