Understanding Phospholipids and Their Role
Phospholipids are a class of lipids that are a major component of all cell membranes [1.6.1]. They are essential for numerous bodily functions, from providing structure to cells to regulating cellular processes [1.6.1, 1.7.1]. The body can produce its own phospholipids, but they are also obtained from foods like eggs, soybeans, red meat, and whole grains [1.7.3, 1.7.4]. Due to their integral role in health, especially brain and liver function, phospholipids are popular dietary supplements, with common types being phosphatidylcholine and phosphatidylserine [1.7.3, 1.7.6]. While beneficial effects have been noted in various studies, it's crucial to be aware of the potential side effects associated with their supplementation [1.7.1].
General and Common Side Effects
For most people, taking phospholipid supplements at recommended doses is unlikely to cause severe issues [1.6.3]. However, some individuals may experience mild and temporary side effects. The most frequently reported adverse effects are related to the gastrointestinal system [1.6.1, 1.2.2].
Commonly reported side effects include:
- Gastrointestinal Distress: This is the most prevalent category of side effects and can manifest as stomach upset or pain, nausea, bloating, and diarrhea [1.2.2, 1.2.4, 1.6.2]. These symptoms are more likely to occur with high doses [1.3.1].
- Excessive Sweating: Some users of phosphatidylcholine have reported increased perspiration [1.2.1, 1.3.3].
- Decreased Appetite: High doses of lecithin, a common source of phosphatidylcholine, may lead to a reduced appetite [1.3.1].
- Insomnia: Phosphatidylserine, particularly at doses over 300 mg, can cause sleeplessness or insomnia [1.4.2, 1.2.3].
Most of these side effects are temporary and may resolve on their own as the body adjusts or by discontinuing the supplement [1.2.2]. Taking supplements with meals can sometimes help mitigate gastrointestinal issues [1.2.2].
Side Effects of Specific Phospholipids
Different types of phospholipid supplements have slightly different side effect profiles.
Phosphatidylcholine (PC)
Often derived from lecithin, PC is used for memory and liver health [1.7.3]. Oral supplementation is generally well-tolerated. Doses up to 30 grams daily have been used in studies for up to 6 weeks [1.2.4].
- Oral Side Effects: Besides general GI upset and sweating, it can sometimes cause a fishy body odor at very high doses (over 20 grams daily of pure choline, but not typically with phosphatidylcholine) [1.3.1, 1.2.1].
- Injection Side Effects: When used for fat reduction via injection, it can cause significant site reactions like irritation, swelling, redness, itching, burning, and pain [1.2.6]. In rare cases, it can cause an inflammatory reaction in fatty tumors, potentially requiring surgical removal [1.2.1].
Phosphatidylserine (PS)
PS is popular for its role in cognitive function, memory, and reducing exercise-induced stress [1.7.4]. It is considered possibly safe for most adults and children for short-term use [1.4.2].
- Common Side Effects: The primary side effects, especially at doses above 300 mg, are insomnia and stomach upset [1.4.2, 1.4.4]. Other less common effects include gas, headache, and skin rash [1.2.3].
- Source Concerns: Historically, PS supplements were made from cow brains, which raised concerns about transmitting diseases like mad cow disease. While there are no known cases of this happening, most supplements are now made from soy or cabbage to avoid this risk [1.4.6].
Krill Oil
Krill oil is a source of omega-3 fatty acids bound to phospholipids, which may enhance their absorption [1.5.3].
- Common Side Effects: Similar to fish oil, it can cause heartburn, fishy burps, stomach upset, and diarrhea [1.5.1, 1.5.5].
- Allergies: Individuals with shellfish allergies should avoid krill oil [1.5.2, 1.5.6].
Comparison of Common Phospholipid Supplements
| Supplement Type | Primary Use(s) | Common Side Effects | Key Considerations |
|---|---|---|---|
| Phosphatidylcholine | Liver health, memory, fat metabolism [1.7.3] | Stomach upset, sweating, diarrhea [1.2.1] | High doses may worsen depression; can cause severe injection site reactions [1.3.1, 1.2.6]. |
| Phosphatidylserine | Cognitive function, ADHD, exercise recovery [1.7.4] | Insomnia, stomach upset (especially >300mg) [1.4.2] | May have blood-thinning effects; plant-based sources are recommended [1.7.4, 1.4.6]. |
| Lecithin (Soy/Sunflower) | Food additive, cholesterol management [1.6.1, 1.6.5] | Diarrhea, nausea, stomach pain [1.6.2] | Generally recognized as safe (GRAS); people with soy allergies should check the source [1.6.3, 1.6.4]. |
| Krill Oil | Source of phospholipid-bound omega-3s, heart health [1.5.3] | Fishy aftertaste, heartburn, loose stools [1.5.4] | Avoid if allergic to shellfish; can slow blood clotting [1.5.6, 1.5.1]. |
Drug Interactions and Safety Warnings
It is crucial to consult a healthcare provider before taking phospholipid supplements, especially if you have pre-existing conditions or are on medication.
- Blood Thinners: Phosphatidylserine and krill oil may have blood-thinning effects and can increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs like warfarin, aspirin, or clopidogrel [1.7.4, 1.5.1].
- Alzheimer's and Cholinergic Drugs: Both phosphatidylcholine and phosphatidylserine can increase levels of acetylcholine in the body. Taking them with acetylcholinesterase inhibitors (e.g., donepezil) or other cholinergic drugs used for Alzheimer's or glaucoma could increase effects and side effects [1.8.1, 1.8.3].
- Anticholinergic Drugs: Conversely, phospholipids might decrease the effectiveness of drying medications (anticholinergics) used for allergies or depression [1.8.1, 1.8.3].
- Diabetes Medications: Krill oil might lower blood sugar levels, potentially causing blood sugar to drop too low when combined with diabetes medications [1.5.4].
- Depression: High-dosage phosphatidylcholine supplementation may worsen depression in some individuals and should not be used for this condition without a physician's supervision [1.3.1].
Conclusion
Phospholipid supplements like phosphatidylcholine and phosphatidylserine are generally safe for most people and can offer benefits for brain, liver, and cellular health. However, what are the side effects of taking phospholipids? They primarily involve mild, temporary gastrointestinal issues such as stomach upset and diarrhea, especially at higher doses. More specific side effects, like insomnia from phosphatidylserine, can also occur. The most significant risks stem from potential interactions with medications, particularly blood thinners and drugs affecting acetylcholine levels. As the FDA does not regulate supplements for safety and purity in the same way as prescription drugs, it is essential to choose reputable brands and consult a healthcare professional before adding any phospholipid supplement to your regimen to ensure it is appropriate and safe for you [1.6.3, 1.8.6].
Authoritative Link: For more in-depth information on phospholipids and their health effects, a valuable resource is the peer-reviewed article on Health effects of dietary phospholipids from PubMed Central. [1.7.1]
