Get A Drip offers therapies including the "slim drip", "anti-ageing drip" and "mood-boost drip" at locations such as Westfield shopping centre in London.
The British Pregnancy Advisory Service (BPAS) said there was "no evidence" its treatment could improve fertility.
Get A Drip defended the product's nutritional benefits but apologised for "insensitivity".
The company, which opened its clinic in the west London shopping centre earlier this year, says it aims to take a wellness trend that began in high-end clinics into the main stream.
It says it employs medical staff, including qualified doctors and nurses, and administers vitamins and minerals along with rehydrating saline solution directly into customers' veins.
Products start at £75 for "basic hydration" - using a solution of salt, bicarbonate, potassium and calcium - and rise to £3,000 for a three-stage "skin brightening" therapy, which adds the antioxidant glutathione and a high dose of vitamin C.
Richard Chambers, the company's founder, said he stood by the benefits of the vitamins and minerals in the fertility drip but conceded: "We understand that the issue of fertility is much deeper than nutrition."
"We are deeply sorry for the insensitivity of the fertility drip and apologise wholeheartedly for any upset caused," he said.
But he said IV drip therapy was "an effective, medically supported treatment to help the body reach optimal nutrition" for people who were not absorbing sufficient nutrients through the gut.
People given the IV therapies were given a "thorough medical consultation", including medical history, a pulse check, blood-pressure reading and temperature check, he said.
Katherine O'Brien, associate director of communications and campaigns at BPAS, said the fertility drip offered an unproven "quick fix at an extortionate cost".
"There is no evidence that an IV drip of any combination of vitamins can improve a woman's fertility," she said.
"In promising hope to women at a very desperate time, we are concerned that, aside from providing no real benefit, these drips may be causing real damage to women's emotional wellbeing."
The only medically recommended supplements for women trying to conceive are folic acid and vitamin D, said Gwenda Burns, head of operations of Fertility Network UK.
Companies charging sums such as £250 for an IV vitamin drip were "exploiting their customers and offering false hope", she said.
Tom Dolphin, a consultant anaesthetist, highlighted the company's therapies on social media calling them a "dubious, costly medicalisation of basic nutrition/hydration".
"It's an expensive way of filling your bladder," he told the BBC. "People who are healthy definitely don't need IV drips."
While a long-term vitamin deficiency could affect aspects of health, including fertility, he said a one-off IV drip would not help.
He said: "If you've got a chronic deficiency, you should be having oral supplements on an ongoing basis."
A spokeswoman for the Medicines and Healthcare Products Regulatory Agency (MHRA) said clinics offering IV nutritional therapies had to make it clear if they were offered for "non-medicinal purposes".
She said IV vitamin therapies that made medical claims needed to be licensed and tested for "safety, quality and efficacy", as well as complying with legislation on advertising.
"The MHRA has previously taken action against a number of clinics who have advertised IV vitamin and mineral drips for medical purposes," she said.
Article: www.bbc.co.uk 2nd July 2019