If celebrity endorsers like Reese Witherspoon, Oprah Winfrey, Drew Barrymore, and Gwyneth Paltrow are promoting a memoir from their billionaire friend, which boasts an incredible journey of self-discovery, there might be more beneath the surface.

This week, we got a deeper look, thanks to a major New York Times article that explored the backstory of Amy Griffin’s influential memoir, “The Tell.”

And the article is far more compelling than the book itself.

Since the memoir’s release in March, Griffin has embarked on a rapid promotional tour, receiving praise from her famous friends, such as Mariska Hargitay and Martha Stewart, along with glowing coverage in numerous media outlets.

Barrymore, on her daytime show, held Griffin’s hand for an uncomfortable seven plus minutes as she gushed that the book was a “literary masterpiece” (!) and would be a “catalyst to others finding the bravery to come out with their truths.”

In “The Tell,” Griffin — who through her G9 Ventures invests in female founded brands like Goop, Spanx and Bumble — recounts a harrowing story of violent childhood sexual abuse she allegedly endured at the hands of a teacher.

However, her memories were recovered during therapy sessions while under the influence of the drug MDMA — a practice that is illegal and was rejected by the FDA last year.

(Griffin and her hedge-funder husband, John Griffin have funded trials into therapeutic MDMA use through their foundation).

The illegality is part of a disclaimer Winfrey makes in the beginning of a sit-down interview with Griffin to welcome the new author into her vaunted book club. The two spoke in front of an audience of middle-aged women, who appeared to be experiencing a contact high from the therapized language pumped out by the pair.

Predictably, the book — which Griffin was reportedly paid nearly $1 million to write — became a New York Times bestseller and a staple in the suburban moms’ reading diet this summer.

“A jigsaw puzzle took place over my head,” writes Griffin referring to the realization of her violent trauma, which gave her more understanding of her life, her choices, and her unrelenting pursuit of perfection.

But how real were those neatly fitting puzzle pieces, given their source?

The Times spent three months investigating. They spoke to people in Amarillo, Texas, where Griffin, whose family owned a chain of convenience stores, grew up in an idyllic setting.

And they uncovered large holes in her story and highlighted the ethical issues about basing such serious accusations on recovered memories.

MDMA advocate Rick Doblin, who connected Griffin with her therapist, told the paper most memories that surface under these conditions are often “symbolic.”

“You have to be somewhat dubious, I guess, about recovered memories,” he said.

She sought to bring the man she accused to justice, but it was past the statute of limitations. In a troubling twist, Griffin writes an attorney told her not to disclose to police that the memories occurred while using illegal psychedelics.

However, the alleged attacker didn’t get off free. Though the teacher is given a fake name in the book, people recognized him from Griffin’s descriptions anyway. Her family members also reportedly shared his name around town, and in the book proposal sent out to publishers, the teacher’s real name was used.

Yet he has a squeaky clean record, and no other alleged victims have emerged since the book was published. Furthermore, they reported he wasn’t told about the book or accusations before it was published.

Now retired, no one has seen the man around town for months.

Griffin, who has been sitting for friendly interviews for months, declined to speak to the Times. Her lawyer bristled at the paper sending pages of questions.

Though she wasn’t able to pursue the case criminally, she told Winfrey that her journey was in unburdening herself to others, taking this “tragedy and turned it into this tapestry of relationships.”

Memoirs are rarely fact checked. Who could forget Winfrey’s one time pet James Frey who fabricated parts of “A Million Little Pieces.” In 2015, The Post’s Isabel Vincent uncovered several outright lies in “Primates of Park Avenue” by socialite Wednesday Martin.

But many take them as objective truth – and as impetus to change their own lives. How many women ditched their jobs and jumped on a plane after reading “Eat, Pray, Love”?

And how many, in search of healing or finding their own trauma, will follow Griffin’s path?

As more layers are peeled back, this starts to feel less like a memoir and more like a reckless celebrity infomercial for psychedelics.

We can’t know if Griffin disturbing account is true or not.

But perhaps in our own quests for fulfillment, we shouldn’t be so eager to gobble up what is served to us by billionaire investors and pampered celebrities businesswomen as gospel.

Take small bites and wash it down with a nice glass of cynicism.