Deepinder Goyal Defends Temple Wearable, Cites $30 Mn Spent on R&D

Deepinder Goyal says Temple has spent $30 Mn developing its brain-monitoring wearable, including $20 Mn of his personal money, as he defends the startup against allegations that its core health claims are scientifically unfounded.

Goyal, who left the CEO role at Eternal, parent of Zomato, to lead Temple, published a statement addressed to "Concerned Indian Doctors" on social media. He said the company is raising additional 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," Goyal wrote. He also pointed to a 14-day, no-questions-asked return policy as evidence the product would be validated by the market.

What did the doctors actually say?

Hepatologist Dr Cyriac Abby Philips, known online as The Liver Doc, called the device "the biggest health scam and wellness fraud in India" in an Instagram post. He argued the sensor can only detect blood rushing to the face, not cerebral activity.

Gurugram-based gastroenterologist Dr Zubin Sharma noted that blood reaches the brain through arteries in the neck and the back of the head, not through the temple area where the wearable sits.

Critics on social media also observed that studies published on Temple's website were not peer-reviewed and were funded and conducted by the company itself. Goyal's "Gravity Ageing Hypothesis", which links long-term gravitational effects on blood circulation to ageing, drew similar scrutiny. Philips renewed his criticism in a reply to Goyal's post, challenging the device's brain blood-flow claims and Temple's proprietary "Entropy" score.

Goyal responded that many wearable makers first relied on internal studies before external validation. Temple plans to release pre-prints ahead of peer-reviewed publications, and expects independent studies once the device ships widely.

Is it a medical device?

In a follow-up post, Goyal drew a clear line: "Temple is a fitness tracker, and wellness device. We are not a medical device." He acknowledged the product has not been clinically validated.

Pre-orders opened on November 1 at a listing price of INR 85,000 per unit. Devices are hand-made to order and expected to ship roughly three months after purchase, starting in early 2027.

Goyal framed his motivation in personal terms. "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," he said. "I am not staking a reputation earned over 20 years on making a quick buck."

How did Temple get here?

The venture grew out of Continue Research, Goyal's personal health initiative launched in 2024. It stayed largely under wraps until November 2025, when it unveiled the Gravity Ageing hypothesis proposing that gravity's effect on cerebral blood flow is an overlooked contributor to human ageing. Temple emerged around the same time as its commercial arm, with Goyal seen wearing a prototype near his temple.

The device has since shrunk. Goyal revealed a smaller version in August, claiming it is less than half the size of the earlier iteration. Temple works with contract manufacturers Zetwerk and Ethereal Machines to scale production while keeping some manufacturing in-house.

In February, Temple raised $54 Mn (about INR 493 Cr) in a seed round at a post-money valuation of roughly $190 Mn. Goyal led the round with an investment of a little over INR 100 Cr. Steadview Capital, Peak XV Partners, Vy Capital and Info Edge Ventures also participated, along with more than 30 employees.

The startup widened its scope in July 2026, acquiring London-based longevity medicine practice Longevous for an undisclosed sum to bring clinical and scientific expertise in-house.

Temple's next test arrives with first shipments in early 2027, when the promised pre-prints, independent studies and return-policy refunds will show whether Goyal's bet on unvalidated science can survive contact with paying customers.