Phosphatidylserine (abbreviated Ptd-L-Ser or PS) is a phospholipid component, usually kept on the inner-leaflet (the cytosolic side) of cell membranes by an enzyme called flippase. It increases the rate of protein synthesis during periods normally marked by muscle breakdown and can aid in memory function.

Where is it Found?
The Body - phosphatidylserine can be produced in the body. Within the body, higher concentrations of phosphatidylserine are found within the internal organs.
The brain, liver and kidney have relatively high concentrations of phosphatidylserine.

Food Sources of Phosphatidylserine - phosphatidylserine can also be obtained externally from dietary sources. PS can be found in meat, but is most abundant in the brain and in innards such as liver and kidney. Only small amounts of PS can be found in dairy products or in vegetables, with the exception of white beans.Oily fish such as mackerel and tuna are rich sources of phosphatidylserine; specifically soybean oil, is the primary dietary source for PS, followed by wheat gluten and peanuts.more limited concentrations of phosphatidylserine can be found in dairy products, rice and root vegetables like carrot, beet, potatoes.

Phosphatidylserine is also used for improving mental functioning in young people and improving athletic performance.

Dosage
Most people take in about 130 mg of phosphatidylserine through their diet. For improvement in mental functions, phosphatidylserine is given in 100 mg doses two to three times daily. Athletes taking phosphatidylserine to build muscle might take 800 mg a day. The total amount of phosphatidylserine in the body is about 60 grams, 30 grams of which is in the brain.

Possible Side-Effects / Precautions / Possible Interactions
Phosphatidylserine is POSSIBLY SAFE for most people. It’s been used in research studies for up to six months. Phosphatidylserine use can, however, cause side effects including insomnia and stomach upset, particularly at doses over 300 mg. There is some concern that products made from animal sources could transmit diseases, such as mad cow disease. To date, there aren't any known cases of humans getting animal diseases from phosphatidylserine supplements, but look for supplements made from plants to be on the safe side.

Special Precautions & Warnings
Pregnancy and breast-feeding: Not enough is known about the use of phosphatidylserine during pregnancy and breast-feeding. Be on the safe side and avoid use.
Phosphatidylserine can also cause the throat to swell, another allergic reaction.
A feeling of being out of breath or outright breathing difficulty can occur while using phosphatidylserine. If this occurs stop use immediately.
Rashes and/or itching can occur with the use of phosphatidylserine. This allergic reaction symbolizes an inability for the body to handle the medicine properly.

Possible Interactions
Some drying medications are called anticholinergic drugs. Phosphatidylserine might increase chemicals that can decrease the effects of these drying medications.

Some drying medications include atropine, scopolamine, and some medications used for allergies (antihistamines) and for depression (antidepressants).
Medications for Alzheimer's disease (Acetylcholinesterase (AChE) inhibitors) interacts with phosphatidylserine. It might increase a chemical in the body called acetylcholine. Medications for Alzheimer's disease called acetylcholinesterase inhibitors also increase the chemical acetylcholine. Taking phosphatidylserine along with medications for Alzheimer's disease might increase effects and side-effects of medications for Alzheimer's disease.

Some acetylcholinesterase medications include donepezil (Aricept), tacrine (Cognex), rivastigmine (Exelon), and galantamine (Reminyl, Razadyne)
Various medications used for glaucoma, Alzheimer's disease, and other conditions (Cholinergic drugs) interacts with phosphatidylserine.

Research Studies / References