Does David Sinclair recommend Leucine?
David Sinclair recommends Leucine in some contexts, but has also raised cautions.
Published research rates it moderate evidence. Of David Sinclair's 7 tracked claims, 0 are supported or partially supported by studies on PubMed.
Evidence last reviewed May 2026
David Sinclair on Leucine — 7 claims
“try to focus on plant based food more often so that there are periods during the week when there are aren't as many leucine, isoleucine and valine molecules floating around in your body so that you have a chance for your mTOR down regulation to recycle proteins”
Having periods during the week with fewer leucine, isoleucine, and valine molecules allows mTOR to downregulate and activate autophagy, which is beneficial for recycling proteins and may help prevent accumulation of damaged proteins as seen in Alzheimer's disease.
“because of leucine's effects there are many people, particular fitness communities to ingest more leucine to maximize their wellness cases muscle growth but also just wellness... give you immediate benefits. You'll bulk up more. You'll feel better immediately, but based on the research, it's at the expense of”
Ingesting more leucine to maximize muscle growth or wellness, as promoted in fitness communities, may provide immediate benefits but at a long-term expense according to the research.
“there are three ones that are particularly important to know about. It's leucine, isoleucine and valine also known as the branched chain amino acids. And these are used by the body to sense protein intake. And the sensor is this protein complex we talked about called mTOR.”
Leucine, isoleucine, and valine (branched chain amino acids) are sensed by the body to detect protein intake, with mTOR as the sensor.
“And when there's lots of these three branched chain amino acids particularly leucine it will be activated. And this mTOR the role is to say wow I've got lots of amino acids let's build muscle, let's repair cells, let's do all good stuff”
When leucine (and other branched chain amino acids) are abundant, mTOR is activated, signaling the body to build muscle and repair cells.
“when there's lots of these three branched chain amino acids particularly leucine it will be activated. And this mTOR the role is to say wow I've got lots of amino acids let's build muscle, let's repair cells, let's do all good stuff”
Leucine (along with isoleucine and valine) activates mTOR, which signals the body to build muscle and repair cells.
“when I think of meat, thinks amino acids, right? I think amino acids... including leucine... the first step is acid in your stomach is going to break down that meat into amino acids and then your your microbiomes can utilize a lot of them and then those amino acids are also going to leach into your bloodstream.”
Amino acids including leucine from meat are sensed by mTOR after digestion and absorption into the bloodstream.
“lack of amino acids, leucine, lysine and valine. mTOR and it's that up sirtuin, down MTOR that is hugely beneficial and turns on all of the body's defenses, the pro chewing up the old proteins, giving us more energy, repairing cells, all of that.”
Lack of amino acids including leucine during fasting suppresses mTOR and upregulates sirtuins, which is hugely beneficial and activates the body's defenses.
Other supplements David Sinclair discusses
Claims are extracted from publicly available podcasts and videos, attributed to their source, and compared against PubMed research. This is educational information only — consult a healthcare provider before starting any supplement.
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