“MDMA” is a lurid, over-sexed, drugged–out soap opera set at the tail end of the Go Go ’80s, when Reagan was King and “Molly” was his Queen.

It may pass itself off as “cautionary,” but this is exploitation, the sort of faintly alluring journey through hell that reminds us that every generation craves its “Beyond the Valley of the Dolls” or “Less Than Zero.”

First-time writer-director Angie Wang didn’t attract “Zero” level A-listers for her titillating indie expose. But she got some decent players to flesh out her fleshy fandango through promiscuity and profitability, temptation and tragedy.

It was the Club Era, before Raves arrived, when most people called the hot new drug “E,” “Ecstasy,” but the science nerds know it as MDMA, 3,4 Methyl​enedioxy​methamphetamine — “Molly” to her friends.

Angie is a college freshman chemistry major in the right/wrong place at the right/wrong time to get a taste of the drug itself, and with the brains and means to make it herself and finance college, partying and even generous Big Sistering with her profits.

Former child actress Annie Q of TV’s “Are We There Yet?” and “The Leftovers” stars, and can’t really play Angie as naive, lonely and a long way from home falling under bad influences. She may weep at the father (Ron Yuan) who cannot say “I love you” back to her when she boards the bus for a cross-country trip to college in San Francisco. But when she gets there and meets her party-debutante roommate (Francesca Eastwood), she’s more than ready to knock back and few drinks and “Go find some fun.”

A fraternity party leads her to the hunky swimmer all the coeds crave (Pierson Fode). And he has these pills he’d love to share — Ecstasy.

“The club drug? HIT me!”

That puts her in his bed and in a mind to find a way to make this drug, not-yet-banned but only made in Germany, after school. A lab assistant job should do the trick. Maybe with a little help from the straight-arrow lab partner who has a crush on her (Scott Keiji Takeda).

Angie may burn through Chinese restaurant cook dad’s cash too fast and look for a quick and dirty solution to that problem. She may be promiscuous. But flashbacks show us the open warfare her parents engaged in and the rape she suffered as a younger teen.

And she’s not so rotten that she doesn’t have time to Big Sister Bree, the young daughter of a local crackhead.

The “lurid” here comes from Wang’s frenetic club scenes, lots of extreme closeups, garish lighting, dancing and snorting away, and from the broad strokes Wang and her actress (Yetide Badaki) paint the crack mom with.

The story arc is straight-up drug era parable — prodigal daughter, missing mom, a how-to primer on getting started in the drug trade (ID the right clubs and the right frat boys for distribution). Angie has no sooner growled “I know how to take care of myself,” when the ways she doesn’t start to pop up.

As the story is told in a flashback with Angie as a drug-addled cage dancer in a club in the opening scene, any notion of surprise is abandoned straight out.

Annie Q is better at the cold-hearted, calculating Angie than the “freshman” and Big Sister Angie. It’s a performance and characterization steeped in sexual experience, risky behavior and vocal fryyyyyyyyyy.

Eastwood, you-know-who’s daughter with Frances Fisher, is likewise too old for the “freshman” stuff. But if you’re making a point about drugs and booze and a bad home life that makes girls grow up too fast, 26 year-olds are the way to go. I guess.

The “Valley of the Dolls” connection is underlined with sex scenes — a threesome, of course — because if there’s one thing about Molly’s rep that resonates, it’s how she fires up the libido.

The only reason to make this a period piece is catching the drug at its pre-crackdown, any science nerd can make it birth — that, and the cheaper Frankie Goes to Hollywood music clearances for the club scenes.

Wang seems to have sincerely set out to make a cautionary tale, “inspired by true events,” with a dedication in the opening suggesting she knew a victim of MDMA. But what she’s releasing is straight-up exploitation, and a film too cautious to work on that level, too torrid to play the “Stay off drugs!” card.

MPAA Rating: unrated, violence, drug abuse, explicit sex

Cast:Francesca Eastwood, Annie Q., Pierson Fode, Scott Keiji Takeda

Credits: Written and directed by Angie Wang. A Shout! Factory release.

Running time: 1:38