Following criticism over Temple’s credibility and scientific validation, Deepinder Goyal defended the research behind the wearable and said it is a fitness tracker and not a medical device
Several medical experts on social media had questioned Temple over whether the wearable can reliably measure cerebral blood flow
Critics also pointed out that studies published on Temple’s website were not peer-reviewed, and were funded and conducted by the company itself
Addressing social media debates over the scientific validity of Temple
’s eponymous brain-monitoring wearable, founder Deepinder Goyal issued a statement directed at “Concerned Indian Doctors”, asserting confidence in the R&D behind the wearables.
Goyal pointed out that Temple had already spent $30 Mn on its development, including $20 Mn of his personal money. He also noted that the company is raising funding from its employees and customers.
“Selling a few thousand devices recovers a small fraction of this investment. A scam that pays nothing is not a scam anyone would run,” the CEO wrote in his post.
Goyal further said the product’s 14-day no-questions-asked return policy would validate its product in the market.
On questions over Temple’s credibility and scientific validation, he argued that many wearable makers initially relied on internal studies before publishing external validation. He said the company would release pre-prints before peer-reviewed publications and it expects independent studies to emerge once the device becomes available more widely.
In a follow-up post, Goyal also said, “Temple is a fitness tracker, and wellness device. We are not a medical device,” adding that the device hasn’t been clinically validated.
Important to highlight that pre-orders for the wearable officially opened on November 1, with a hefty listing price of ₹85,000. Units are hand-made to order and expected to begin shipping roughly three months after purchase, starting in early 2027.
For context, several medical experts had criticised Temple over its claim that a wearable sensor placed near the temple can reliably measure cerebral blood flow.
Hepatologist Dr Cyriac Abby Philips, popularly known as The Liver Doc, published an Instagram carousel calling the product “the biggest health scam and wellness fraud in India,” saying the device can only detect when blood rushes to one’s face.
Gurugram-based gastroenterologist Dr Zubin Sharma also noted that blood flows to the brain via arteries in the neck and back of head, not the temple.
Additionally, many on social media pointed out that studies published on Temple’s website were not peer-reviewed, and were funded and conducted by the company itself. They also raised questions about the validity of Goyal’s Gravity Ageing Hypothesis, which links the long-term effects of gravity on blood circulation to ageing.
In fact, Dr Philips doubled down on the criticism of Temple in a reply to Goyal’s latest post, calling out Temple’s claims of reading blood flow to the brain and the company’s explanation of its proprietary ‘Entropy’ score.
Goyal’s move into brain-monitoring wearables has been taking shape through a series of bets on longevity research. This began with his personal research initiative Continue Research, which he referred to as his personal health and wellness venture back in 2024.
The initiative remained largely under wraps for over a year before unveiling its first hypothesis, Gravity Ageing, in November 2025. The hypothesis proposed that gravity’s effect on cerebral blood flow (CBF) could be an overlooked contributor to human ageing.
Temple emerged around the same time as a commercial extension of this research. Inc42 first reported in November 2025 that Goyal was exploring a wearable device company focused on health monitoring. The device, which he had been seen wearing near his temple, was being used experimentally to measure blood flow to the brain in real time.
“I left the Eternal CEO role to chase purpose with Temple. This is not about money. I have enough of it to last for generations. My incentives are fully aligned with getting the science right. I am not staking a reputation earned over 20 years on making a quick buck,” Goyal said.
On the product front, Temple has been developing a wearable that sits on the forehead near the temple and tracks signals associated with cerebral blood flow. Goyal revealed a smaller version of the device in August, claiming it was less than half the size of its earlier iteration. It has worked with contract manufacturers Zetwerk and Ethereal Machines to scale production, while retaining some manufacturing capabilities in-house.
The startup began taking shape as a standalone venture earlier this year. In February, Temple raised $54 Mn (around ₹493 Cr) in a seed funding round at a post-money valuation of approximately $190 Mn. The round was led by Goyal, who invested a little over ₹100 Cr, with participation from Steadview Capital, Peak XV Partners, Vy Capital, Info Edge Ventures, among others. More than 30 employees also participated in the round.
Temple subsequently expanded its ambitions beyond hardware. In July 2026, it acquired London-based longevity medicine practice Longevous for an undisclosed amount, bringing clinical and scientific expertise into the business.
Source: Inc42
