Harvard geneticist David Sinclair’s business pitch has remained largely the same: Aging can be slowed or reversed, and we are about to figure out how.

“A lot of my colleagues dislike that phrase, the reversibility of aging,” he told a roomful of longevity investors. “But I truly believe that, based on my lab’s research and now others, that aging can be reversed. If I can make one medicine that would change people’s lives, I’d be very happy.” Sinclair also has co-founded companies that sell directly to consumers products such as supplements and tests that purport to show one’s “biological age.” He has also helped raise more than $1 billion.

But according to a report in The Wall Street Journal, the investors have almost nothing to show for it. Four companies trying to develop longevity drugs have gone bankrupt or largely halted operations. Another four either haven’t yet tested their drugs or gene therapies in humans or have run only small-scale trials that make it difficult to know whether a drug will work.

Sinclair has drawn criticism from fellow scientists, who say he exaggerates the findings and implications of age-related research. The board of the Academy for Health and Lifespan Research, a group Sinclair co-founded and led, asked him to resign as president earlier this year after he was quoted as saying a dog chew sold by a company he co-founded reversed aging in dogs.

Possible Preaching Angles:

It looks like we’re still living in the reality of the Fall, that human beings will age, grow old, and eventually die. We are still mortal!