Highlights
- Doctors say claims that Deepinder Goyal's Temple tracks blood flow to the brain lack peer-reviewed evidence
- Goyal calls it a wellness device; Temple admits its key metrics rest on "emerging science"
- India's health ministry is silent, while US regulators have challenged similar claims by Whoop
DEEPINDER GOYAL, Indian billionaire who co-founded Zomato, is facing a backlash from prominent Indian doctors over Temple, a Rs 85,000 ($907) wearable that claims to show how well the brain is being supplied with blood in real time.
The critics say those claims are not backed by peer-reviewed research and want the device brought under the purview of medical regulators. Goyal insists Temple is a fitness tracker, not a medical product. The company itself concedes that its headline metrics rest on "emerging science" and that some will eventually need regulatory approval.
The row raises a question health-tech companies face worldwide: when does a fitness gadget become a medical device? It also matters because Temple is being shown off by two of India's most recognisable sports stars, cricket captain Shubman Gill and Olympic medal-winning badminton player PV Sindhu.
What Temple says it can do
Temple is less than an inch (2.54cm) wide and weighs under two grams. It sticks to the side of the head, between the forehead and the ear.
According to promotional materials, its BrainFlow feature shows how well the brain is being supplied with blood in real time. A second feature, Entropy, is said to detect how hard the body is working to shed heat.
The company says the device also measures thermal, immune, digestive, cognitive and emotional readings that help people transform how they regulate their health. Its website says it is working on detecting conditions such as snoring and jaw clenching. The device comes in six colours.
Why doctors are sceptical
The sharpest criticism has come from hepatologist Cyriac Philips, known online as "TheLiverDoc". He has used his X account, which has 328,000 followers, to call Temple "the biggest health scam".
"People must be aware of wellness hacks such as wearables also, even though they are not marketed as health devices," he told Reuters.
On a prime-time TV discussion, paediatrician and nephrologist Sanjeev Bagai called Temple a "gimmick", saying it had "no formal approval or clearance".
Other doctors have questioned the science behind the BrainFlow claim. Jason Philip wrote on X that assessing blood flow to the brain is not easy. He said optical signals taken over the temple would only give data on the "superficial temporal artery", which supplies blood to the face and skin, not the brain.
What Goyal and Temple say
Goyal has hit back at the doctors, saying Temple is a "fitness tracker, and wellness device", not a medical one.
In a statement to Reuters, Temple described BrainFlow and Entropy as new metrics "with emerging science". It said more research would follow and that some metrics would eventually need regulatory approval.
India's health ministry did not respond to Reuters' queries. The government has so far not reacted to the public debate.
Overseas, regulators have been more active in drawing the line between fitness and medical features. Some Apple Watch features, such as hypertension notifications, have received US Food and Drug Administration clearance as software-based medical features.
Last year, the FDA warned Whoop that its wrist-worn fitness tracker's blood-pressure feature looked like a medical one. The company disputes that view.
Goyal, 43, is best known for co-founding Eternal, which houses Zomato, India's biggest listed food-delivery company. Eternal has a market value of about $35 billion.
He stepped down as Eternal's chief executive this year to focus on Temple. The company raised $54 million in February at a valuation of about $190m. Its advisory board includes professors from the University of Ottawa and Harvard.
Goyal says the device has received orders from more than 62 countries since November 1.
The outcome now rests on two things: whether Temple publishes evidence for its metrics, and whether Indian regulators decide the device is more than a fitness tracker.
Temple has said more research will follow, but has not said when. The doctors leading the criticism are pressing for regulators to step in.













