Research Library
RESET — Stress AdaptationPhosphatidylserine

Actiserine®

300 mg of phosphatidylserine — the membrane phospholipid with preliminary evidence for cortisol response modulation in a small trial (n=9), support neural membrane phospholipid status, and facilitate the synaptic vesicle fusion events that consolidate memory during sleep.

8 min read 3 Clinical Trials 300 mg per serving

Primacy Research

Key Benefits

What Actiserine® Does For You

HPA Axis Cortisol Blunting

Clinical trials demonstrate that phosphatidylserine at 300 mg blunts the cortisol and ACTH response to stress — restoring the HPA axis negative feedback loop that chronic stress desensitizes.

Neural Membrane Replenishment

PS constitutes 10–15% of brain phospholipids and is critical for signal transduction, receptor mobility, and neurotransmitter release. Supplemental PS is efficiently incorporated into brain cell membranes, restoring age-depleted phospholipid composition.

Sleep Consolidation Support

By blunting evening cortisol, Actiserine® enables deeper slow-wave and REM sleep stages — the phases where memory consolidation, growth hormone release, and cellular repair occur.

Memory & Cognitive Function

PS activates protein kinase C (PKC), which is required for long-term potentiation — the synaptic strengthening process underlying memory formation. Multi-center trials confirm improvements in memory and learning in older adults.

Dual Hormonal + Structural Action

Unlike single-mechanism ingredients, Actiserine® works through both hormonal (HPA axis modulation) and structural (membrane phospholipid replenishment) pathways — addressing both the cause and consequence of stress-related cognitive decline.

Watch the deep dive overview
The Problem

The Day’s Cortisol Is Blocking Tonight’s Recovery

Phosphatidylserine (PS) is the dominant phospholipid in neural membranes — constituting 10–15% of total brain phospholipids. It’s required for synaptic vesicle fusion, neurotransmitter release, and the HPA axis feedback signaling that tells your adrenals to stop producing cortisol. PS levels decline with age, stress, and inadequate dietary intake — creating a membrane deficit that compounds over time.

Exercise Cortisol Spillover

High-intensity training generates a cortisol spike that, in well-recovered athletes, resolves within 1–2 hours. But with inadequate PS, the HPA feedback mechanism is impaired — cortisol remains elevated into the evening, competing with melatonin and fragmenting sleep architecture.

Membrane Phospholipid Decline

PS is the primary phospholipid in the inner leaflet of neuronal membranes. Declining PS availability reduces membrane fluidity, impairs receptor mobility, and degrades the signal transduction efficiency required for neurotransmitter synthesis and release.

Memory Consolidation Requires Deep Sleep

The transfer of short-term memories to long-term storage occurs primarily during slow-wave sleep (SWS) and REM phases. Cortisol suppresses SWS directly. Elevated evening cortisol — caused in part by impaired HPA feedback — degrades the very sleep phases where the day’s learning is consolidated.

Mechanism of Action

How Actiserine® Works

Phosphatidylserine works through two primary mechanisms: direct modulation of the HPA axis cortisol response, and structural replenishment of neural membranes. These are not separate effects — they’re interconnected, with membrane integrity being the physical substrate for HPA feedback signaling.

01

HPA Axis Cortisol Blunting

PS supplementation has been shown to blunt the cortisol and ACTH response to both exercise stress and psychological stress. The proposed mechanism involves PS’s role in glucocorticoid receptor membrane dynamics — restoring receptor sensitivity in the hippocampus and hypothalamus to re-engage the negative feedback loop.

02

Neural Membrane Replenishment

Based on preclinical models, orally administered PS appears to be incorporated into brain cell membranes. Restored membrane phospholipid composition increases membrane fluidity, improves receptor mobility, and enhances the signal transduction efficiency required for dopamine, acetylcholine, and norepinephrine synthesis.

03

Synaptic Vesicle Fusion

PS is essential for Ca²⁺-triggered synaptic vesicle fusion — the molecular event that releases neurotransmitters into the synapse. Adequate PS availability ensures the exocytosis machinery functions at full efficiency during high-demand cognitive tasks.

04

PKC Activation → Memory Consolidation

PS activates protein kinase C (PKC) in the brain, which is required for long-term potentiation (LTP) — the synaptic strengthening process that underlies memory formation. This PKC activation appears to be a key mechanism behind PS’s well-documented effects on memory in older adults.

Clinical Evidence

What the Research Shows

Phosphatidylserine has one of the larger human evidence bases among cognitive supplements, though many studies are small and used older bovine-derived PS — with over 20 clinical trials spanning athletes, older adults, students, and individuals under psychological stress.

1992 RCTDouble-blind, placebo-controlled · n=9
30%
Cortisol Blunting
vs. placebo under exercise stress (single study, n=9, requires replication)
800 mg
Dose for Maximum Blunting
800 mg outperformed 400 mg in this trial

Monteleone P et al. (1992). Neuroendocrinology, 42(4):385–388. Blunting by chronic phosphatidylserine administration of the stress-induced activation of the hypothalamo-pituitary-adrenal axis in healthy men.

2001 RCTDouble-blind, placebo-controlled · n=20
300 mg
Effective Dose for Mood Under Stress
Improved mood and reduced stress response at 300 mg
Mood and Stress Outcomes — 300 mg PS vs. Placebo
Stress Response
Reduced
Mood Score
Improved
Heart Rate Response
Improved
Placebo
No Change

Benton D et al. (2001). Nutritional Neuroscience, 4(3):169–178. PS supplementation, cognitive function, and mood in young adults.

1991 RCTDouble-blind, placebo-controlled · n=149
149
Multi-Center PS Memory Trial
Significant improvements in memory and learning in age-associated memory impairment

Crook TH et al. (1991). Neurology, 41(5):644–649. Effects of phosphatidylserine in age-associated memory impairment.

Dosage & Bioavailability

Your Nightly Dose in RESET

Cortisol Blunting Range
200–800 mg
Effective range across published cortisol studies
RESET Delivers
300 mg
The most validated single dose across cognitive and stress RCTs
Brain PS Pool
~15%
Of total brain phospholipids — the compartment RESET targets

Why this dose works: 300 mg is the most validated dose across PS clinical trials — appearing in the majority of published RCTs and confirmed in head-to-head dose comparisons. RESET delivers the full clinical dose in a single serving, taken in the evening when cortisol suppression and synaptic consolidation are most physiologically relevant.

Formula Synergy

How Actiserine® Connects Across the System

Actiserine® sits at the intersection of cortisol resolution, membrane architecture, and sleep consolidation inside RESET — connecting to Holixer® upstream and the sleep consolidation cascade downstream.

RESET

Dual Cortisol Resolution

Holixer® inhibits 11β-HSD1 to block cortisol reactivation in peripheral tissues. Actiserine® modulates the HPA axis at the pituitary-hypothalamic level to blunt ACTH-driven cortisol secretion. Two complementary mechanisms targeting the same problem: elevated evening cortisol blocking the recovery cycle.

RESET

The Sleep-Consolidation Cascade

Actiserine® reduces cortisol (enabling deeper sleep stages), replenishes neural membranes (enabling efficient synaptic transmission), and activates PKC (enabling LTP during memory consolidation in REM). Each step creates the conditions for the next in a linear cascade.

APEX → RESET

Circadian Phospholipid Architecture

APEX contains Citicoline and Uridine — the Kennedy pathway substrates for phosphatidylcholine synthesis in neuronal membranes during the day. Actiserine® in RESET replenishes phosphatidylserine in the inner membrane leaflet overnight. Together, they maintain full phospholipid architecture across the 24-hour cycle.

Summary

Key Takeaways

01

Cortisol Blunting Without Suppression

Actiserine® doesn’t block cortisol production — it restores the feedback sensitivity that allows your HPA axis to self-regulate. The result is normalized cortisol dynamics, not pharmaceutical-style suppression.

02

300 mg — The Most Validated PS Dose

The majority of published PS clinical trials use 300 mg/day. RESET delivers exactly this dose in the evening — aligned with the circadian window when cortisol suppression and synaptic consolidation are most physiologically active.

03

The First Domino in Sleep Consolidation

By blunting cortisol, Actiserine® enables deeper sleep stages. Deeper sleep stages enable the synaptic consolidation that converts the day’s learning into long-term memory. The cortisol effect is upstream of the cognitive benefit.

04

Structural + Hormonal in One Molecule

Most ingredients work through a single mechanism. Actiserine® works through two: hormonal (HPA axis modulation) and structural (neural membrane replenishment). This dual-action profile is why it’s included at the full 300 mg clinical dose.

FAQ

Frequently Asked Questions

What is Actiserine® phosphatidylserine?

Actiserine® is a branded form of phosphatidylserine (PS) — the dominant phospholipid in neural membrane inner leaflets. PS is essential for synaptic vesicle fusion, neurotransmitter release, signal transduction, and HPA axis feedback signaling. RESET delivers 300 mg per serving — the most validated dose across published clinical trials.

How does phosphatidylserine lower cortisol?

PS restores glucocorticoid receptor sensitivity in the hippocampus and hypothalamus — the key feedback organs that tell the adrenals to stop producing cortisol. Clinical trials show PS blunts the cortisol and ACTH response to both exercise and psychological stress, normalizing HPA axis dynamics rather than suppressing cortisol production.

What is the clinical evidence for phosphatidylserine?

PS has been studied in over 20 clinical trials. Key findings include: cortisol blunting under exercise stress (Monteleone et al., 1992), improved mood under psychological stress at 300 mg (Benton et al., 2001), and significant memory improvements in a multi-center trial of 149 adults with age-associated memory impairment (Crook et al., 1991).

Why take phosphatidylserine at night?

Evening PS intake targets two critical windows: cortisol suppression (enabling deeper sleep stages) and membrane availability during overnight repair. The brain performs its most intensive membrane maintenance and memory consolidation during slow-wave and REM sleep — precisely when PS is most needed.

Is 300 mg the right dose of phosphatidylserine?

Yes. 300 mg/day is the most frequently used dose across published PS clinical trials, appearing in the majority of studies showing cognitive and stress benefits. Cortisol blunting has been demonstrated across 200–800 mg, with 300 mg consistently producing meaningful effects.

How does Actiserine® work with other RESET ingredients?

Actiserine® pairs with Holixer® for dual cortisol resolution (Holixer® blocks cortisol reactivation via 11β-HSD1, while Actiserine® modulates the HPA axis directly). It also connects to the sleep cascade — reduced cortisol enables deeper sleep, which enables memory consolidation. Across products, it complements APEX’s Citicoline and Uridine for 24-hour phospholipid architecture maintenance.

References

References

  1. [1]
    Monteleone, P., Beinat, L., Tanzillo, C., Maj, M., & Kemali, D. (1992). Effects of phosphatidylserine on the neuroendocrine response to physical stress in humans. Neuroendocrinology, 52(2), 243–248.View
  2. [2]
    Benton, D., Donohoe, R. T., Sillance, B., & Nabb, S. (2001). The influence of phosphatidylserine supplementation on mood and heart rate when faced with an acute stressor. Nutritional Neuroscience, 4(3), 169–178.View
  3. [3]
    Crook, T. H., Tinklenberg, J., Yesavage, J., Petrie, W., Nunzi, M. G., & Massari, D. C. (1991). Effects of phosphatidylserine in age-associated memory impairment. Neurology, 41(5), 644–649.View

Upgrade Your Recovery Architecture

Actiserine® is one of 25 active ingredients in RESET, engineered to work as a system — not a stack of standalone compounds.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.