Phytosome vs. "Liposomal": Why the Way PEA Is Delivered Matters

If you read supplement labels, you have almost certainly seen the word "liposomal" printed with some confidence. It has become shorthand for "absorbs better," and it sells. What gets far less attention is whether the product in the bottle is actually liposomal in any meaningful sense, and whether that even matters for the ingredient it is wrapped around. Delivery science is one of the few places where the difference between a real technique and a borrowed term shows up directly in whether a compound reaches your bloodstream. This is worth a deeper look, because for certain actives the delivery method is not a detail. It is the difference between a dose that works and a dose that passes through you.

Key Takeaways

• Bioavailability, not the number printed on the label, determines how much of an active ingredient your body can actually absorb and use.
• A true liposome is a phospholipid bilayer vesicle; many products marketed as "liposomal" simply blend an ingredient with oil or lecithin, which does not form a real liposome.
• A phytosome, or phospholipid complex, is a distinct and well-characterized approach in which the active is molecularly bound to a phospholipid to improve absorption of a poorly-soluble compound.
• Palmitoylethanolamide, or PEA, is naturally fat-loving and poorly water-soluble, which is exactly the kind of active for which a delivery system is worth taking seriously.
• In a meta-analysis of 11 randomized double-blind trials involving 774 patients, PEA reduced pain with a large effect size, underscoring why getting a therapeutic amount absorbed matters.¹

What "Bioavailability" Actually Means

Bioavailability is the proportion of a substance that reaches systemic circulation in a form your body can use. It is the honest number behind every absorption claim. A capsule can contain a generous milligram count of an active and still deliver very little of it to your tissues if that active is poorly soluble, broken down before absorption, or simply not taken up efficiently across the gut wall.

This is why the dose on the label and the dose your body receives are two different things. For water-soluble compounds the gap is often small. For fat-loving, poorly water-soluble compounds it can be large, and it is precisely these ingredients that benefit from a delivery system designed to close that gap. Understanding this is the whole reason delivery technology exists, and the whole reason the "liposomal" label became valuable enough to be applied loosely.

What a True Liposome Is: A Bilayer Vesicle, Not a Blend

A true liposome is a microscopic sphere built from a phospholipid bilayer, the same class of molecule that forms your own cell membranes. Phospholipids have a water-loving head and a fat-loving tail, so in the right conditions they self-assemble into a double-layered shell that encloses a small pocket of fluid. An active ingredient can be carried inside that protected core, shielded as it travels through the digestive tract.

Constructing a genuine liposome takes specific manufacturing conditions and verification that the vesicles actually formed. This is where the marketing and the science tend to part ways. Many products labeled "liposomal" have not formed liposomes at all. They are an active simply mixed with an oil or with lecithin, a phospholipid source, without the structured bilayer that defines a liposome. The word travels well on a label; the structure does not always travel with it. "Liposomal" has become, in a meaningful share of the market, a marketing term rather than a verified description of what is in the capsule.

None of this means phospholipids are the problem. It means the claim is often doing more work than the formulation behind it.

What a Phytosome Is: A Phospholipid Complex, Not a Loose Mixture

A phytosome, also called a phospholipid complex, is a different structure and a legitimately characterized one. Instead of trying to trap an active inside a vesicle, a phytosome chemically binds the active molecule to a phospholipid such as phosphatidylcholine, often sourced from sunflower lecithin. The phospholipid effectively escorts the active across the gut wall, which is itself made of phospholipid membranes.

The distinction is worth stating plainly, because the two terms are often blurred:

The reason a phospholipid complex matters is not novelty. It is that the approach is well-suited to exactly the kind of ingredient that is otherwise hard to absorb: a poorly-soluble, fat-loving active. That is where the conversation should turn from labels to the specific molecule in question.

Why This Matters Specifically for PEA

Palmitoylethanolamide (PEA) is a fatty-acid compound the body produces naturally, and it has genuine evidence behind it for pain. A meta-analysis of 11 randomized, double-blind trials involving 774 patients found that PEA significantly reduced pain, with a large pooled effect size (SMD 1.68, 95% CI 1.05 to 2.31).¹ A larger 2025 meta-analysis of 18 studies and 1,196 patients extended that body of evidence.² Its mechanism is well-mapped: PEA activates PPAR-α receptors and helps stabilize mast cells and microglia, the immune cells involved in neuroinflammation.³ Its safety record is reassuring, with more than 20 trials and roughly 2,000 patients showing no serious adverse events.⁴

Here is the catch that makes delivery non-negotiable for PEA specifically. PEA is lipophilic, meaning it is fat-loving and poorly soluble in water. In its raw form it does not dissolve or absorb well, which is why the amount on a label can badly overstate the amount your body receives. This is the textbook case for a phospholipid-based delivery system: pair a poorly-soluble, fat-loving active with a phospholipid that helps it cross the fat-based membranes of the gut, and you narrow the gap between the labeled dose and the absorbed dose.

So the question is not whether PEA works. The evidence says it can. The question is whether a given PEA product is built to actually deliver it, or whether it is relying on a big number and a well-traveled marketing word.

Reading a Delivery Claim: What Separates Technique From Term

The practical takeaway is that a delivery claim is only as good as the structure behind it. A few honest questions cut through most of the noise. Is the term describing a verified structure, or is it a loose blend borrowing a scientific-sounding name? Is the delivery approach matched to the ingredient, meaning a fat-loving active paired with a phospholipid-based method rather than a mismatched one? And is the formulation transparent about what it uses and why, rather than leaning on a single buzzword to carry the claim?

None of this requires a chemistry background. It requires knowing that "liposomal" on a label is not a guarantee, that a phospholipid complex is a real and characterized technique, and that the ingredient and the delivery method have to fit each other. For a poorly-soluble active like PEA, that fit is the entire point.

The Bigger Picture

Delivery is where a good ingredient either becomes a working dose or stays a number on a label. This is the thinking behind how Relivaid delivers its PEA: not as raw powder and not as a loosely-mixed "liposomal" blend, but as a phytosomal phospholipid complex, a bio-optimized form in which the PEA is molecularly bound to phospholipids to support absorption of an otherwise poorly-soluble active. It is paired with ginger delivered through a polar/non-polar sandwiching approach and 50 mg of caffeine as a complementary ingredient, in a formula designed for occasional aches, pains, and inflammation. The point is not a bigger label number. It is a delivery method matched to the molecule, so the dose you read is closer to the dose you receive.

References

1. Lang-Illievich K, et al. Nutrients. 2023. doi:10.3390/nu15061350.

2. Viña I, López-Moreno M. Nutrition Reviews. 2025. doi:10.1093/nutrit/nuae203.

3. Di Stefano V, et al. Biomedicines. 2025. doi:10.3390/biomedicines13061271.

4. Nestmann ER. Food Science & Nutrition. 2016. PMC5332261.