Ketosis in a Capsule? The Curious Case of 1,3-Butanediol

Not long ago, I wrote about supplements and medications—half scolding, half defending, and admittedly walking the tightrope between “don’t rely on pills” and “don’t dismiss them either.” So the irony isn’t lost on me that I’m back here, writing about… well… a supplement.

This one’s called 1,3-butanediol (BD), a compound that the body converts into β-hydroxybutyrate (βHB), a ketone body. Translation: it can put you into ketosis without you having to banish bread, pasta, and fruit from your plate. For anyone who’s ever looked at a ketogenic diet and thought, “I’d rather eat my shoelaces than give up carbs forever,” the idea of a ketosis-inducing supplement probably sounds like a miracle in a bottle.

What the Research Says

A recent animal study looked at whether BD could mimic the neurological benefits of a ketogenic diet. Rats fed BD for 14 days showed less inflammation, less oxidative stress in the hippocampus (the brain’s memory HQ), and better markers of synaptic health compared to their normal-diet peers. Interestingly, even when researchers accounted for calorie restriction—a known driver of improved brain health—BD still offered unique benefits. Proteins critical for neuron survival and communication (BDNF, synaptophysin, and synaptotagmin) increased specifically in the BD group.

In short: the supplement didn’t just act like a diet pill. It seemed to directly support brain resilience.

The Catch

Before anyone rushes to Amazon, a reality check:

• These were rats, not humans.
• The study lasted two weeks (roughly a year in rat time, but still a far cry from the decades it takes for dementia to develop in humans).
• The level of ketosis achieved in these rats was modest compared to a full ketogenic diet. In other words, while BD nudged their metabolism toward ketosis, it didn’t fully replicate the diet’s effects.

That’s why the authors themselves—and I—would caution against viewing BD as a magic bullet for Alzheimer’s, memory decline, or even everyday brain fog. It’s preliminary, promising, and worth watching—but not ready for prime time.

Where This Leaves Us

Here’s where the irony circles back. Supplements like BD highlight a truth I keep coming back to: sometimes, exogenous molecules can nudge physiology in interesting, maybe even protective, ways. But they should never distract us from my 6 pillars of bulletproof aging: nutrition, exercise, sleep, connection, cognition, and home modifications.

If you’re chronically underslept, sedentary, and eating ultraprocessed food all day, popping BD isn’t going to save your hippocampus. At best, it’s an adjunct—something to consider after you’ve tended to the fundamentals.

That’s the tension I sit with when I write about supplements. They’re not villains, but they’re not saviors either. They’re tools. And like any tool, their usefulness depends on the bigger structure you’re building.

So, do I “hate” supplements? Not at all. I just refuse to give them top billing in the story of longevity. Think of them as the supporting cast, not the lead role.

References

1. Cigliano L, De Palma F, Petecca N, et al. 1,3-butanediol administration as an alternative strategy to calorie restriction for neuroprotection – Insights into modulation of stress response in hippocampus of healthy rats. Biomed Pharmacother. 2025;182(117774):117774. doi:10.1016/j.biopha.2024.117774
2. Zhao M, Huang X, Cheng X, et al. Ketogenic diet improves the spatial memory impairment caused by exposure to hypobaric hypoxia through increased acetylation of histones in rats. PLoS One. 2017;12(3):e0174477. doi:10.1371/journal.pone.0174477
3. Zhao Q, Stafstrom CE, Fu DD, Hu Y, Holmes GL. Detrimental effects of the ketogenic diet on cognitive function in rats. Pediatr Res. 2004;55(3):498-506. doi:10.1203/01.PDR.0000112032.47575.D1