Doctor Criticises ‘Temple’ Device Worn by Zomato CEO Deepinder Goyal, Calls It Scientifically Baseless

A doctor who previously worked with the All-India Institute of Medical Sciences has slammed `Temple’, an experimental device worn by Deepinder Goyal, calling it scientifically unsound. Dr Suvrankar Datta, a physician-scientist, is also warning people against spending money on what he described as a “fancy toy”. Dr Datta’s comments have come after Goyal, CEO of Zomato, who appeared on a YouTube podcast, was recorded wearing a small sensor attached to his temple. The wearable, which looked unusual, quickly caught viewers’ attention online. “As a physician-scientist and one of the earliest researchers in India in arterial stiffness and pulse wave velocity (2017), which predicts cardiovascular mortality, I can assure you that this device currently

has zero scientific standing as a useful device,” Dr Datta wrote his views on social media’s X (formerly Twitter).

As a physician-scientist and one of the earliest researchers in India in Arterial Stiffness and Pulse Wave Velocity (2017) which predicts cardiovascular mortality, I can assure you that this device currently has 0 scientific standing as a useful device and do not waste your hard… https://t.co/pm0pxGRycd

— Dr. Datta M.D. (AIIMS Delhi) (@DrDatta_AIIMS) January 4, 2026

As part of his efforts into brain health and a provocative “gravity ageing” idea, Goyal and his team have come up with the experimental gadget, which he says is a non-invasive monitor intended to measure blood flow to the brain in real time. However, according to Dr Datta, the gadget is simply a waste of money, as it is completely unscientific. “Do not waste your hard-earned money on buying fancy toys that billionaires can afford to waste money on. If you are one, then go ahead,” he added.

What does the `Temple' measure?

Goyal says Temple is linked to his privately funded research initiative based on what he calls the ‘Gravity Ageing Hypothesis’. Although he has not published full technical specs, the type of continuous, wearable cerebral monitoring Goyal describes is an active area of academic work. Researchers and start-ups are developing small optical and sensor patches that use techniques such as functional near-infrared spectroscopy (fNIRS), diffuse speckle contrast flow, or diffuse correlation spectroscopy (DCS) to estimate regional cerebral blood flow and oxygenation without surgery. These approaches allow mobile tracking of brain perfusion and cognitive fatigue in research settings — but they remain primarily research tools rather than proven consumer health devices. Goyal has also committed $25 million, which is around ₹225 crore, of his personal funds to the research. He has clarified that the device is not a Zomato product, is still experimental, and is not available for public or commercial use. “It’s open-source, backed by science, and shared as part of our common quest for scientific progress on human longevity,” Goyal said in the podcast with Raj Shamani.

I’m not sharing this as the CEO of Eternal, but as a fellow human, curious enough to follow a strange thread. A thread I can’t keep with myself any longer. It’s open-source, backed by science, and shared with you as part of our common quest for scientific progress on human… pic.twitter.com/q2q3tRj3Jd

— Deepinder Goyal (@deepigoyal) November 15, 2025

Read more: What Is The ‘Temple’ Device Deepinder Goyal Has Been Wearing — And Does It Really Help Reverse Ageing?

What is gravity ageing?

According to experts, the gravity hypothesis is based on the fact that gravity reduces blood flow to the brain since humans spend most of their lives upright, with the brain positioned above the heart. As years pass, the reduced circulation accelerates brain ageing – thereby affecting the rest of the body. Goyal, giving examples from bats, which are usually inverted and live significantly longer for their size, and to yoga practices involving ‘head below heart’ postures, said that there is a link between height and lifespan, suggesting shorter individuals may live longer because blood travels a shorter distance against gravity to reach the brain.