Kim Richards -- On The Hunt For Xanax At LA Smoke Shops (PHOTO)

Kim Richards is in a desperate state ... so desperate she's going to smoke shops to score Xanax.

We're told Richards went to a smoke shop in Sherman Oaks several times this week, asking for the Rx drug. People in the shop say employees were perplexed because drugs aren't sold there, but Kim insisted a family member claimed she could score the drugs there.

We're told Kim was turned away each of the 3 separate times she showed up. On one occasion, someone in the store watched her leave and then go inside another smoke shop nearby.

As for why Kim was on the hunt for Xanax, she says she needs it because she has a foot injury ... which obviously makes no sense because Xanax is for anxiety.

As we reported, Kim recently left rehab for substance abuse.