A healthy-lookin' Demi Moore touched down in L.A. on a private jet last night ... the first time she's been seen in public since her whip-it induced medical emergency back in January ... and TMZ has the pics.

Moore -- who was reportedly vacationing in Turks and Caicos following a stint in treatment -- was greeted with a big 'ol bear hug by a mystery woman who was waiting on the tarmac.

Moore had been off the radar ever since the January 23 incident ... when she was hospitalized for seizure-like symptoms after inhaling nitrous oxide at her L.A. home.

Demi's rep said the actress was seeking "professional assistance" to treat exhaustion and improve her overall health ... but wouldn't reveal where she got treatment.

There have been multiple reports by various outlets Demi Moore is getting treatment at the famous Cirque Lodge in Orem, Utah.  

TMZ has confirmed with multiple sources familiar with the situation that Demi Moore is not at Cirque Lodge.

Moore has not been seen out in public ever since her whip-it induced medical emergency on January 23.

As TMZ previously reported, Moore had been partying with her daughter Rumer in Los Angeles ... and had to be hospitalized. Her rep later said she was being treated for stress and exhaustion.

Just 9 days before her whip-it induced medical emergency ... Demi Moore partied under the radar at Miley Cyrus' BF's birthday bash in L.A. ... you know, the one with the penis cake ... more evidence that Demi was desperately clinging on to her fading youth.

Multiple sources who were at Club Icon on January 14 tell us ... Demi was hanging out with her daughter Rumer and some young friends ... mostly kickin' it in the VIP section.

We're told Demi was drinking Red Bull all night ... a drink she's been obsessively sucking down for years. We're told she left with Rumer sometime after midnight. 

A few days later, Demi was seen clubbing with Rumer around Hollywood ... and on January 23rd, she was hospitalized after inhaling nitrous oxide in the form of whip-its, a drug that's super popular with high school kids.

People familiar with the situation tell us ... it's not hard to connect the dots. The woman who became famous for what people thought was eternal youth became a believer in the illusion, and it manifested itself in various ways -- partying with her daughter and her 20-something friends, obsessing over her body image, and finally using drugs that appeal to people more than half her age.

Sarah Jessica Parker was hard at work on the L.A. set of "Lovelace" on Wednesday ... taking over the role Demi Moore vacated after she was hospitalized last week.

Parker is rocking a long blonde wig to play '70s feminist icon Gloria Steinem in the biopic of late porn star Linda Lovelace.

As we previously reported, Demi dropped out of the project in the wake of her medical emergency ... when she inhaled dangerous amounts of nitrous oxide in the form of whip-its, lapsed into semi-consciousness and experienced seizure-like symptoms.

On Set Blow-ups

Rumer Willis knows if her mother Demi Moore has entered a rehab center for substance abuse ... and Saturday night she MAY have revealed the truth on camera.

Rumer was arriving to Comme Ca restaurant in West Hollywood ... when a paparazzo asked her, "Is Demi in rehab?"

It sounds like Rumer says, "No" ... but her purse was over her face, so it's hard to tell if Rumer said the word ... or if it came from another woman in the area.

Check out the video ... decide for yourself.

Rumer Willis returned to the Hollywood party scene last night ... slinking into a SAG Awards after-party just 6 days after her mother partied her way into the hospital last week.

Rumer -- who was at her mom's home when Demi went into a semi-conscious, convulsive state last Monday -- was seen entering the legendary Chateau Marmont hotel on the Sunset Strip last night ... by herself.

As we previously reported, Rumer and Demi had been partying together in Hollywood just 2 weeks before Demi's medical emergency.

We're told Demi is still receiving treatment for substance abuse.

Party All the Time

The L.A. City Attorney recommended that all references to whip-its be redacted from the Demi Moore 911 tape -- and the recommendation was followed ... TMZ has learned.

Sources tell us ... the Deputy City Attorney assigned to the case heard references to whip-its and felt it would be an invasion of privacy if that information was released to the public -- so it was cut out of the tape, along with specific references to other drugs.

TMZ broke the story ... paramedics on scene were told Demi had used whip-its to inhale nitrous oxide just before she lapsed into semi-consciousness and exhibited seizure-like symptoms.

Now we know the person who called 911 also told the dispatcher about the whip-its.

Rumer Willis was at her mom's home when Demi Moore went into a semi-conscious, convulsive state.

If you listen to the 911 tape -- around the 00:54 mark -- you'll hear the caller ask, "What is the address Ru?"

What's interesting ... Demi was clearly smoking something and, we're told, inhaling nitrous oxide with her daughter right there.

Rumer, who is 23, was partying with Demi just 2 weeks ago in Hollywood.

TMZ has obtained the 911 call placed moments before Demi Moore was rushed to an L.A. hospital Monday night -- after her friend told paramedics she had inhaled too much nitrous oxide ... aka whip-its.

There is utter confusion at the beginning of the call -- the dispatcher doesn't know which department should handle the call.  The woman says Demi smoked something -- not marijuana -- similar to incense and she's having convulsions.  The person says Demi was barely conscious. 

Capt. Jaime Moore with the L.A. City Fire Dept. tells TMZ ... the FD redacted portions from the tape.  Sources in the City Attorney's office tell us references to specific drugs and other substances Demi ingested were redacted because of privacy issues.  As TMZ first reported, one of the friends at Demi's house told paramedics she has been using whip-its -- nitrous oxide.

The person says she's been taking some other stuff recently but she didn't know what it was ... and she was having "issues" lately.  
 
The caller said "She's burning up." 

Demi Moore was obsessively drinking Red Bull in weeks preceding her 911 emergency, but we've learned her addiction to Red Bull is a decade old.

Moore -- a recovering addict -- had cases and cases of Red Bull delivered to her home as early as 2002. Sources connected with Red Bull North America tell us ... Demi was so dependent on the energy drink, the company used her to market the product. 

Sources from the Red Bull company tell us ... the delivery schedule was frequent enough to ensure Demi was never without Red Bull.

The Sun published a story today reporting ... in the months before Demi was hospitalized ... she was using Red Bull in place of food.  

Our sources say ... two weeks before Demi was hospitalized, she went to a Hollywood party and consumed a massive amount of Red Bull ... but never touched alcohol.

Ashton Kutcher finally touched down in LA -- two days after Demi Moore was rushed to the hospital -- looking far more concerned than he did earlier this week in Brazil.

Ashton was spotted partying hard at a Bruno Mars concert -- the day after Demi was hospitalized when she fell into convulsions at home. She was taken by ambulance to a nearby hospital ... where she's been getting treatment for substance abuse.

Demi announced her plans to divorce Ashton back in November.