Before You Pre-Order Deepinder Goyal’s Rs 85,000 Temple on November 1, Read This

Deepinder Goyal's Temple will open for pre-orders on November 1, and the first batch is reported to cost Rs 85,000, including a lifetime subscription. That puts the Zomato founder's brain-tracking wearable in a price band where most buyers will expect proof that it works. Right now, that proof is still thin.

Here is what you are actually paying for, and what you aren't.

What Rs 85,000 gets you

Temple is a small, pill-shaped sensor that sticks to the side of your head, near your temple, using disposable adhesive strips the company calls Grips. It comes in six finishes, three of them limited editions. Each unit is handmade after you order, and delivery is promised within three months, so November buyers should expect theirs in early 2027.

The device uses optical sensors to produce two main readings. BrainFlow tracks relative changes in blood-flow-related signals in your head. The Entropy score, which runs from 1 to 250, is meant to show how much physiological strain your body is under, and it reacts to things like sleep, exercise, caffeine and stress.

The money math

Rs 85,000 is a lot for a wearable, even a premium one. The Oura Ring 5, which launched in India last week, costs Rs 39,900 plus Rs 599 a month for membership. You would have to pay for Oura's membership for over six years before your total spend matched Temple's. Google's Fitbit Air costs Rs 13,999, which means you could buy six of them for the price of one Temple.

The lifetime subscription does work in Temple's favour if you plan to use it for many years. But that only matters if the data it gives you is genuinely useful, and that is where the questions begin.

What it measures, and what it doesn't

The word "relative" matters a lot here. Temple doesn't claim to measure exactly how much blood is reaching your brain. It tracks how certain signals rise and fall over time. That can still be interesting, for instance seeing how your readings change after a bad night's sleep or a strong coffee. But it isn't the same as a medical measurement of brain blood flow.

Temple says so itself. Its terms of use describe the product as meant for general wellness and information, not for diagnosing, treating or preventing any medical condition.

The evidence so far

The main validation data is a study posted on medRxiv in September. It compared BrainFlow with transcranial Doppler ultrasound, a standard hospital method for measuring blood flow in the brain, in 23 healthy adults during exercise and posture-change tests. The two showed a correlation of about 0.8 in those conditions, which is a promising start.

But the study had only 23 participants, all healthy. It is a preprint, which means it hasn't been peer-reviewed, and Temple funded it. A good correlation in a controlled test also doesn't tell us how well the device works in everyday life, or whether its readings can help you make better health decisions.

Doctors and researchers raised similar concerns back in January, when the device first drew attention. At the time, Goyal acknowledged on X that the company hadn't released any official benchmarking data.

The idea behind Temple

Temple grew out of what Goyal calls the gravity ageing hypothesis. The idea is that over a lifetime, gravity makes it harder for blood to reach the brain, and that this reduced flow speeds up ageing and cognitive decline. It is an interesting idea, but it is Goyal's hypothesis, not an established scientific finding.

Goyal clearly believes in it. He has put over $25 million of his own money into longevity research, and Temple raised $54 million earlier this year from backers including Steadview Capital, Peak XV Partners, Kunal Shah, Vijay Shekhar Sharma and Nithin and Nikhil Kamath. That is serious backing, but investor money is not the same as clinical evidence.

So who should buy it

Temple was first described as a performance wearable for elite athletes, and that is probably still the right audience. If you are a serious athlete, a biohacker or someone who enjoys being an early adopter, and Rs 85,000 won't hurt, Temple offers data no other wearable on the market gives you.

For most people, though, an Oura, a Whoop or a Fitbit will cover sleep, recovery and activity tracking for much less money, with years of data behind them. It may be worth waiting for Temple to publish peer-reviewed research and for early buyers to share how useful the readings really are.