Jeffrey Stern’s mother wanted him to have every advantage — from his schooling at Manhattan’s prestigious Dalton School to summer camp in the Berkshires.

So when Jeffrey, at age 11 and 4-foot-1, was a full foot shorter than everyone else in his class, she talked to an endocrinologist, who put him on human growth hormone.

“The doctors said that he was destined to be taller,” Margot Stern said.

Jeffrey now stands 5-foot-7, but that’s not tall enough for the 16-year-old and his mother.

“They said that the height that’s owed to him is around 5-foot-8 or 5-foot-10,” she said. “I was going to give him a chance to achieve his growth potential.”

Jeffrey is just one of at least six sophomores at the private Dalton School taking Humatrope, a designer drug for preteens that some experts call “Miracle-Gro for kids.”

The growth hormones — which are shockingly easy to get — are being used increasingly by wealthy parents looking to give their children a leg up, literally, experts say.

The trend comes thanks to a 2003 change in Food and Drug Administration regulations. Officials ruled that growth hormones were acceptable for any child who falls into the 1.2 percentile of height for their age. Before this, only children with rare medical conditions — such as human growth deficiency or Turner’s syndrome — were considered eligible for treatment.

The average American man is 5-foot-8, and 5-foot-3 is considered the bottom of the normal range, according to the Centers for Disease Control.

Sales of Humatrope, the most widely prescribed growth hormone, shot up 40 percent in 2004. In 2007, manufacturer Eli Lilly reported $440 million in sales for the drug — a 6 percent increase from the year before.

Shortness now is seen as a treatable condition, and parents, without accounting for genetic predisposition, are taking their kids’ height into their own hands.

The trend does not sit well with health insurers.

Aetna covered Jeffrey’s treatments for the last four years, but in April, when his mother changed policies, the company refused to cover the $2,400-a-month shots.

Aetna no longer looked at the 5-foot-7 soccer player’s condition as a growth-hormone deficiency. It now considers his diagnosis to be “short stature,” which it doesn’t cover.

Jeffrey’s mother insists her son suffers from a medical condition. She’s taking Aetna to court in Manhattan to force them to continue the coverage.

“Aetna has medically inhibited Jeffrey Stern’s puberty for two years, and then acting as ‘God,’ determined that his growth would stop on April 1, 2009,” she claims in court papers.

But medical experts question the ethics and effectiveness of such treatments.

“It’s outrageous,” said Dr. Alan Rogol, a professor at the University of Virginia Hospital who specializes in growth and development. “We’re struggling to get kids up to 5 feet. Only in New York on the Upper East Side.”

He said he doubts there will be any benefit to continued treatment. Rogol said Humatrope usually adds only one or two inches to a child’s growth.

“I can certainly see where the insurance company is coming from,” he said.

The growth spurt Jeffrey enjoyed after taking the drugs did not go unnoticed by his classmates’ parents.

“After Jeffrey grew taller than some of the kids in his class, other mothers called me,” Margot Stern said. “Three kids went on it as a direct result of Jeffrey. I think it has something to do with competition, but others were just concerned.”

In Jeffrey’s sophomore class of about 120 students, there are six students taking the drug, Stern said. Statistically speaking, that’s five times the norm if you use the FDA’s “1.2 percentile” rule as a guide.

But doctors often disregard FDA guidelines and prescribe the hormone “off label” to families concerned about their kids’ height.

HGH side effects include headaches, glucose intolerance and hip problems. The long-term risks are still a mystery.

“It’s one thing if your kid has a life-threatening illness, but what’s the threat if your kid is short?” said Susan Cohen, author of “Normal at Any Cost: Tall Girls, Short Boys and the Medical Industry’s Quest to Manipulate Height.”

“We would urge a little more humility in the doctors and caution in the parents. No medication is risk-free.”

Stern insists Jeffrey’s treatments are not about appearances.

“A lot of people think that this is just superficial, but there was clearly something wrong with his hormones,” she said.

From the ages 7 to 11, Jeffrey barely grew. His shoe size in the first grade was the same as his shoe size in the fifth grade. On a summer camp field trip to a New Jersey amusement park, he stood in line for nearly half an hour with his friends for a roller coaster, only to be told he was too short to ride.

“I waited in line for 25 minutes just so the lady could tell me that I couldn’t get on the ride,” Jeffrey recalled.

Margot Stern took Jeffrey to two endocrinologists, who ran tests and determined that at the rate his bones were growing, he would not make it to 5 feet.

Mount Sinai Dr. Madeleine Harbison prescribed two drugs. The first, Lupron, delayed Jeffrey’s puberty so his bones would not age and harden. The second, Humatrope, stimulated growth.

Doctors can determine Jeffrey’s “growth potential” through regular X-rays that show his “bone age.” With these X-rays, they can predict how much longer his bones will grow before they fuse and harden.

“I realize that people are going to hate me because he’s 5-foot-7, but when you’ve been through what we’ve been through, you want to see it through,” Stern said.

Stern pointed to a pencil mark on the closet door in Jeffrey’s room.

“I put 6 feet on the wall just to be hopeful,” she said.

janon.fisher@nypost.com

