Lecithin supplements line the shelves of health food shops, promising everything from sharper thinking to lower cholesterol. But does the science back up these claims? I’ve dug through the research to give you a clear picture of what lecithin can and cannot do.

What is lecithin?

Lecithin is a fatty substance found naturally in both plant and animal tissues. A French chemist named Theodore Gobley first isolated it from egg yolk back in 1846, and the name comes from the Greek word “lekithos” meaning egg yolk.

The stuff you find in supplements is actually a mixture of several compounds: choline, fatty acids, glycerol, glycolipids, phosphoric acid, triglycerides, and most importantly, phospholipids. These phospholipids are critical components of every cell membrane in your body, including phosphatidylcholine, phosphatidylserine, and phosphatidylinositol.

What makes lecithin particularly useful in food manufacturing is its emulsifying properties. It can bind water and fat together, which is why you’ll find it in ice cream, infant formula, bread, margarine, and chocolate. As a supplement, most lecithin comes from soybeans, though you can also find versions derived from eggs, sunflower seeds, or rapeseed.

What are the proven benefits of lecithin?

1. Lecithin may benefit non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) affects a staggering portion of the global population. Some estimates suggest over 30% of people worldwide have fat accumulation exceeding 5% of their liver weight. The condition often goes unnoticed until it progresses, making early intervention potentially valuable.

A 2022 pilot study examined 30 patients with NAFLD who took phosphatidylcholine capsules (300 mg, twice daily, three times a day) for three months. The results showed meaningful reductions in liver enzymes: alanine aminotransferase (ALT) dropped by up to 59.6% and aspartate aminotransferase (AST) by up to 75.4%. The treatment also increased antioxidant markers like glutathione peroxidase and superoxide dismutase 1.

If you’re interested in other supplements for liver health, milk thistle is another option worth researching.

My take: These are promising numbers, but 30 participants over three months is a small study. I’d want to see larger trials before drawing firm conclusions. The mechanism makes biological sense though, since phosphatidylcholine is a key component of liver cell membranes.

2. Lecithin may help ulcerative colitis

Ulcerative colitis causes chronic inflammation of the colon lining, leading to symptoms like frequent diarrhoea, urgent bowel movements, rectal bleeding, and persistent fatigue. Western countries see prevalence rates between 0.02% and 0.23%.

Research has found that phosphatidylcholine forms part of the protective mucus layer in your colon. When levels drop too low, bacteria can more easily penetrate this barrier and trigger inflammatory responses 2.

A meta-analysis of three randomised controlled trials involving 160 ulcerative colitis patients found that sustained-release lecithin preparations (containing 30% phosphatidylcholine) improved remission rates, clinical and endoscopic findings, histological activity, and quality of life 2.

The catch: The sustained-release formulation matters here. Regular lecithin might get absorbed too quickly to reach the colon where it’s needed. And 160 patients across three trials is still relatively modest evidence.

3. Lecithin may support recovery in liver failure

Liver failure represents the severe end of liver disease, requiring intensive care and swift intervention. Whether the underlying cause is acute, acute-on-chronic, or chronic, the liver’s breakdown affects virtually every organ system.

One preliminary randomised controlled trial examined lecithin treatment (350 mg, three times daily for six to eight weeks) in patients with fulminant and subacute liver failure. The lecithin group showed faster recovery from brain lesions and lower mortality rates 3.

Reality check: This is genuinely interesting but very preliminary. Liver failure patients need proper medical care first and foremost. Lecithin might be a helpful adjunct, but we need more studies before making strong recommendations.

4. Lecithin has not shown clear benefits for dementia

Here’s where I need to deliver some disappointing news. Given lecithin’s role in producing acetylcholine (a neurotransmitter involved in memory), researchers hoped it might help with cognitive decline.

A Cochrane systematic review analysed 12 randomised trials looking at lecithin for Alzheimer’s disease, Parkinson’s disease, and subjective memory complaints. The conclusion? Lecithin supplementation did not produce any clear clinical benefit for Alzheimer’s or Parkinson’s disease compared to placebo. There was some suggestion it might help with subjective memory problems, but the evidence wasn’t convincing 3.

If you’re looking for supplements with better evidence for cognitive health, ginkgo biloba and fish oil have been more extensively studied, though results remain mixed.

My honest assessment: The theory made sense, but the data just doesn’t support lecithin for dementia prevention or treatment. This is a case where a plausible mechanism didn’t translate into clinical benefit.

5. Lecithin during pregnancy may reduce psychiatric risks in offspring

This one caught my attention. A double-blind, placebo-controlled trial with 49 children found that those whose mothers took lecithin (specifically phosphatidylcholine) during pregnancy showed fewer attention problems and less social withdrawal on behavioural assessments 4.

The improvement was comparable in magnitude to similar deficits seen in children who later develop schizophrenia. The proposed mechanism involves lecithin activating α7-nicotinic acetylcholine receptors, which influences brain development.

Worth noting: This is fascinating research but extremely preliminary. The sample size is tiny, and we’re talking about preventing something (schizophrenia) that only affects about 1% of the population. Don’t take this as a recommendation to supplement during pregnancy without discussing it with your doctor first.

6. Lecithin may help hypercholesterolaemia

High cholesterol affects a huge portion of the population, with secondary causes accounting for roughly 80% of cases. The remaining 20% stems from genetic abnormalities in lipoprotein metabolism.

A double-blind controlled study lasting two months examined 30 patients with hypercholesterolaemia. Those taking lecithin capsules (500 mg daily) showed significant reductions in total cholesterol and LDL cholesterol compared to placebo 5.

The mechanism likely involves reduced intestinal cholesterol absorption or increased bile acid secretion.

For cholesterol management, red yeast rice and fish oil have stronger evidence bases, though they also come with their own considerations.

My take: The cholesterol-lowering effect is plausible and the study design was decent, but 30 participants for two months is a short proof-of-concept trial. I wouldn’t rely on lecithin alone for managing cholesterol.

7. Lecithin may ease some menopausal symptoms

The transition to menopause brings vasomotor symptoms (hot flashes), joint pain, fatigue, sleep difficulties, and mood changes. About one-third of women experience moderate to severe symptoms.

A randomised, double-blind, placebo-controlled study of 86 women aged 40-60 found that high-dose soy lecithin improved vitality scores (measured using the Profile of Mood States scale), diastolic blood pressure, and cardio-ankle vascular index over eight weeks 6.

If menopause symptoms are a concern, soy isoflavones are another soy-derived option with a larger body of research.

Reality check: The vitality improvement is interesting, but “vitality” is a fairly subjective measure. The cardiovascular markers are more objective and potentially meaningful. Still, this is one study, and the effect on the most bothersome menopausal symptom (hot flashes) wasn’t the focus.

8. Lecithin may help specific cases of bipolar disorder

Bipolar disorder involves alternating episodes of depression and mania, typically emerging in adolescence or early adulthood. Treatment usually involves mood stabilisers and other psychiatric medications.

A case study reported on a boy with hypomania and a DGKH gene variant who showed improvement in hypomanic symptoms and insomnia when phosphatidylcholine was added to his existing treatment 7.

A word of caution: This is literally one case report about a patient with a specific genetic variant. It’s hypothesis-generating at best, not evidence that lecithin helps bipolar disorder generally. Anyone with bipolar disorder should work with their psychiatrist and not self-treat with supplements.

9. Lecithin is used for blocked milk ducts, but evidence is lacking

Blocked or plugged milk ducts are a common breastfeeding challenge. They occur when milk doesn’t drain completely, creating tender lumps that can be quite painful.

Lecithin has become a popular recommendation in breastfeeding circles, with the theory being that it reduces milk viscosity by increasing polyunsaturated fatty acid content. The commonly suggested dose is 3600-4800 mg daily (about 1200 mg three to four times daily).

The honest truth: Despite widespread use, I couldn’t find any published clinical trials actually testing whether lecithin prevents or treats blocked ducts. The Academy of Breastfeeding Medicine mentions it as an option based on anecdotal reports and theoretical mechanisms, but acknowledges the lack of research 8. It’s probably harmless and might help, but we simply don’t know for certain.

Are there any side effects of lecithin?

Lecithin is generally well-tolerated by most people. However, reported side effects include:

Diarrhoea
Excessive sweating
Nausea or vomiting
Abdominal pain or cramping
Feeling of fullness

These side effects tend to occur more frequently at higher doses.

Safety precautions: 7 contraindications

1. Allergic reactions: Lecithin is typically extracted from soybeans, egg yolks, sunflower seeds, or rapeseed. The extraction process may leave residual proteins, meaning people allergic to soy, eggs, or sunflower seeds could potentially react to lecithin. Symptoms might include rash, breathing difficulties, or swelling of the face, lips, tongue, or throat. If you have known food allergies, choose your lecithin source carefully or avoid it altogether.

2. Cardiovascular concerns with TMAO: Your gut bacteria convert choline (a component of lecithin) into trimethylamine, which your liver then converts to trimethylamine N-oxide (TMAO). Higher TMAO levels have been associated with increased risk of major cardiovascular events 9. This doesn’t mean lecithin definitely increases heart disease risk, but it’s worth knowing about, especially if you’re taking it long-term.

3. Potential contribution to fatty liver: Ironically, despite its potential benefits for NAFLD, some research suggests excessive lecithin might actually contribute to lipogenesis and hepatic lipid accumulation 10. The dose probably matters here, and this may not apply to moderate supplementation, but it’s another reason not to go overboard.

4. Anticholinergic drug interactions: Don’t combine lecithin with anticholinergic medications, as they may interfere with each other’s effects. These include atropine, scopolamine, some antihistamines, and certain antidepressants. Consult your doctor or pharmacist if you take any of these.

5. Acetylcholinesterase inhibitor interactions: Lecithin may increase side effects when taken with medications like donepezil, tacrine, rivastigmine, or galantamine (commonly prescribed for Alzheimer’s disease). Both lecithin and these drugs increase acetylcholine activity.

6. Interactions with pilocarpine: If you take pilocarpine for glaucoma or dry mouth, combining it with lecithin could increase the chance of cholinergic side effects.

7. Blood thinner interactions: Research suggests lecithin may increase platelet adhesion 11, potentially reducing the effectiveness of blood thinners like aspirin and warfarin. If you’re on anticoagulant therapy, discuss lecithin use with your doctor.

How much lecithin should you take?

There’s no established optimal dose for lecithin supplementation. Clinical studies have used anywhere from 0.5g to 2g daily for general health purposes, while breastfeeding recommendations suggest 3.6g to 4.8g daily for blocked ducts.

Always follow the dosage on your specific product and consult your doctor or pharmacist if you’re unsure. Starting with a lower dose and increasing gradually may help you avoid gastrointestinal side effects.

Summary

Lecithin shows promise for a few specific conditions, particularly fatty liver disease and ulcerative colitis, where the phosphatidylcholine component appears to offer genuine benefits. The evidence for cholesterol reduction and menopausal symptoms is encouraging but limited.

However, I want to be direct: the evidence doesn’t support lecithin for cognitive decline or dementia despite years of hope and research. For blocked milk ducts, it’s widely used but unstudied. And anyone with bipolar disorder or other psychiatric conditions should work with their healthcare team rather than self-treating.

If you decide to try lecithin, choose a product that matches your dietary restrictions (soy-free options exist), start with a modest dose, and pay attention to any interactions with medications you’re already taking.

References

Gupta P, et al. Phosphatidylcholine supplementation in nonalcoholic fatty liver disease: A prospective pilot study. J Clin Exp Hepatol. 2022;12(3):879-885. PubMed
Stremmel W, et al. Retarded release phosphatidylcholine benefits patients with chronic active ulcerative colitis. Gut. 2005;54(7):966-971. PubMed
Higgins JP, Flicker L. Lecithin for dementia and cognitive impairment. Cochrane Database Syst Rev. 2003;(3):CD001015. PubMed
Ross RG, et al. Perinatal choline effects on neonatal pathophysiology related to later schizophrenia risk. Am J Psychiatry. 2016;173(2):156-163. PubMed
Mourad AM, et al. Influence of soy lecithin administration on hypercholesterolemia. Cholesterol. 2010;2010:824813. PMC
Hirose A, et al. Effect of soy lecithin on fatigue and menopausal symptoms in middle-aged women. Nutr J. 2018;17(1):4. PubMed
Van der Veen JN, et al. Phosphatidylcholine in mood disorders. Brain Res Bull. 2015;115:33-36. PMC
Academy of Breastfeeding Medicine Protocol Committee. ABM Clinical Protocol #36: The Mastitis Spectrum. Breastfeed Med. 2022;17(5):360-376. PubMed
Tang WH, et al. Intestinal microbial metabolism of phosphatidylcholine and cardiovascular risk. N Engl J Med. 2013;368(17):1575-1584. PMC
Lagace TA, et al. Phosphatidylcholine and fat accumulation. J Biol Chem. 2009;284(12):7478-7487. PubMed
Kamimura N, et al. Platelet adhesiveness in hyperlipidemic patients. Thromb Res. 1999;96(4):303-308. PubMed