Exogenous Ketones: from NASA to biohackers
The exogenous ketones fascinate both researchers and longevity enthusiasts. Born from an ambitious military project, they moved from NASA and DARPA labs to the bottles of athletes and biohackers. But what do science and experience really tell us about their role in performance and longevity?
From natural ketosis to exogenous ketones
For more than a century, ketosis has been studied as a survival mechanism. The ketogenic diet has been used since the 1920s to treat drug-resistant epilepsy [1]. During fasting, the liver naturally produces ketones — β-hydroxybutyrate (BHB), acetoacetate, acetone — which act as an alternative fuel source to glucose. These molecules provide stable energy and appear to activate longevity pathways like autophagy and mitochondrial protection [2].
The exogenous ketones (salts and esters) were developed to quickly raise blood ketone levels without undergoing strict fasting or a ketogenic diet.
First and foremost a military and space project
In the 2000s, DARPA (Defense Advanced Research Projects Agency) launched the Metabolic Dominance program. The goal: to provide soldiers with a fuel source capable of performing where glucose reaches its limits — during hypoxia, prolonged stress, or forced fasting [3].It was in this context that Dr. Richard Veech, a biochemist at the NIH and former collaborator of Nobel laureate Hans Krebs, developed the first ketone esters. Unlike salts, these esters could raise blood ketone levels in a stable, predictable way without electrolyte overload.His work quickly showed that it was possible to maintain elevated blood ketone levels for several hours, improving cellular endurance and reducing free radical production [4]. This discovery caught the attention of NASA, which was interested in a metabolic fuel source for astronauts undergoing periods of energy deprivation and weightlessness [5].From there, ketones moved from the status of "survival molecule" to a universal energy candidate, capable of supporting the brain and muscles in the most hostile environments.
Arrival on the market
This research paved the way for two major players:
- H.V.M.N. / Ketone-IQ: pioneers in the commercialization of ketone esters based on DARPA/NIH research, in collaboration with the University of Oxford [6].
- Pruvit: a company that popularized ketone salts through a mass retail network.
Their arrival marked the shift of exogenous ketones from the battlefield to biohackers.
Benefits supported by research and clinical studies
Scientific studies are exploring several potential benefits:
- Brain energy – The brain naturally runs on glucose. But when an exogenous supply of β-hydroxybutyrate (BHB) raises blood ketone levels above a certain threshold, they become a primary fuel source. BHB can then cover up to 70% of the brain's energy needs, with more efficient combustion and fewer free radicals [7][8].
- Athletic performance – In cyclists supplemented with exogenous ketone esters, improved endurance and faster recovery were observed [9].
- Appetite and metabolism – Exogenous ketones modulate satiety hormones, particularly ghrelin, which helps reduce hunger [10].
- Neuroprotection – Trials are exploring the use of exogenous ketones to support brain function and slow the progression of neurodegenerative diseases like Alzheimer's or Parkinson's [11].
- Inflammation – BHB from exogenous supplementation acts as an anti-inflammatory signal by inhibiting the NLRP3 inflammasome [12].
Limitations
- Transient effect
- No lipolysis
- Digestive tolerance
- High cost
The rise in blood ketone levels induced by supplements only lasts 2 to 4 hours, depending on the dose and form (salts vs. esters). Unlike fasting or a ketogenic diet, the body does not develop a lasting metabolic adaptation: once the exogenous ketones are metabolized, the body quickly returns to its carbohydrate-based mode if the diet remains high in sugars.
Unlike endogenous ketosis (where the liver produces ketones by burning fat), supplementation does not cause any breakdown of fat stores. In other words, you can have high blood BHB levels without your body mobilizing its fat reserves. Exogenous ketones provide an external fuel source but do not trigger fat loss.
BHB salts, particularly at high doses, can cause bloating, diarrhea, nausea, or stomach discomfort. This phenomenon is linked to the osmotic load of the accompanying mineral salts (sodium, calcium, magnesium, potassium). Ketone esters are better tolerated, but their bitter taste and high cost limit adherence.
Exogenous ketones, especially in the form of pure esters, are among the most expensive supplements on the market. Prices can range from $5 to $12 per serving for an ester (e.g., Ketone-IQ), compared to $2–4 for salts (e.g., Pruvit, Perfect Keto). Daily use therefore becomes financially unsustainable, especially since the benefits are temporary.
In summary, exogenous ketones are a useful, targeted tool for optimizing certain performances or facilitating a metabolic transition. But they do not replace the metabolic flexibility gained through diet and fasting, nor the deep adaptations that promote longevity.
When to use them wisely?
In a Vāhana approach, exogenous ketones are not a magic solution, but a targeted tool:
- facilitate the transition to ketosis (reduce the "keto flu"),
- support mental clarity during periods of high performance,
- improve endurance performance,
- extend the benefits of a metabolic fasting.
Longevity verdict
Exogenous ketones represent a fascinating innovation born from military and space needs. But they do not replace fasting or metabolic flexibility. Their role is to be a complementary tool — useful, but never central.
True longevity lies in the body's ability to naturally switch between glucose and ketones. Exogenous supplements can help… but cellular training remains the true secret.
References
- Wilder RM. The effects of ketonemia on the course of epilepsy. Mayo Clin Proc. 1921.
- Newman JC, Verdin E. β-hydroxybutyrate: A signaling metabolite. Annu Rev Nutr. 2017;37:51–76. [PubMed PMID: 28715993]
- Clarke K. Metabolic dominance project. DARPA report, 2003.
- Veech RL, et al. Ketone esters as a therapeutic and nutritional supplement. Annu Rev Nutr. 2014;34:253–281. [PubMed PMID: 25087259]
- NASA Tech Briefs. Ketone esters for space applications. 2010.
- Cox PJ, et al. Nutritional ketone ester alters fuel preference and endurance performance in athletes. Cell Metab. 2016;24(2):256–268. [PubMed PMID: 27475046]
- Owen OE, et al. Brain metabolism during fasting. J Clin Invest. 1967;46(10):1589–1595. [PubMed PMID: 6061736]
- Veech RL. The therapeutic implications of ketone bodies. Prostaglandins Leukot Essent Fatty Acids. 2004;70(3):309–319. [PubMed PMID: 14769489]
- Evans M, et al. Exogenous ketone supplements and endurance exercise. Front Physiol. 2017;8:848. [PubMed PMID: 29163018]
- Stubbs BJ, et al. Appetite suppression and exogenous ketones. Obesity. 2018;26(2):269–273. [PubMed PMID: 29235169]
- Kashiwaya Y, et al. Ketone bodies and neuroprotection. J Lipid Res. 2013;54(8):1980–1998. [PubMed PMID: 23649663]
- Youm YH, et al. The ketone metabolite β-hydroxybutyrate blocks NLRP3 inflammasome–mediated inflammatory disease. Nat Med. 2015;21(3):263–269. [PubMed PMID: 25686106]
