Meta Information
ID:glynac
Name:
Schema Version:2.4_uniform_evidence_2026_06_18
Created
2026-05-21T22:30:00Z
Model
phase-a-upgrade-claude-sonnet-4.6
Interactions
Target id:
/class/nitrates
Target name:
Nitrate Medications
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
The N-Acetylcysteine (NAC) component of GlyNAC can significantly amplify the blood pressure-lowering effects of nitrate medications (e.g., nitroglycerin), potentially leading to severe headaches, dizziness, and dangerous drops in blood pressure.
Actionable advice:
GlyNAC should not be used at all when taking any prescribed nitrate medications.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
N-acetylcysteine (NAC) has been shown to potentiate the haemodynamic and antiplatelet effects of nitroglycerine (NTG) in man, and to limit the development of haemodynamic tolerance to NTG.
Label source:
PubMed: Nitroglycerine/N-acetylcysteine in the management of unstable angina pectoris. (PMID 3137075)
Action type:
avoid
Target id:
/class/chemotherapy-radiation
Target name:
Cytotoxic Cancer Therapies (Chemotherapy & Radiation)
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
As a potent antioxidant precursor, GlyNAC could theoretically interfere with the effectiveness of chemotherapy or radiation, which often rely on generating oxidative stress to destroy cancer cells.
Actionable advice:
GlyNAC should not be taken during active cancer treatment without explicit approval from an oncologist.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
In the placebo group, one patient with FIGO Stage IB cancer received radiation therapy and the patient with FIGO Stage IVB cancer received chemotherapy and hormonal therapy.
Label source:
Action type:
avoid
Target id:
/class/anticoagulants-antiplatelets
Target name:
Anticoagulants and Antiplatelets
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
The NAC component has mild antiplatelet properties that may increase the risk of bleeding when combined with blood-thinning medications like warfarin, aspirin, clopidogrel, or DOACs.
Actionable advice:
It is important to talk to a doctor before using GlyNAC while taking any blood-thinning medication.
Validation status:
validated_via_fda_label
Evidence tier:
tier_a
Evidence basis:
fda_label_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Major bleeding episodes were not more frequent among patients receiving aspirin plus warfarin than among those receiving warfarin alone, but the incidence of minor bleeding episodes was higher in the combined therapy group.
Label source:
Action type:
informational_none
Target id:
/dietary/high-protein-meal
Target name:
High-Protein Meal
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
1
Hours after target:
2
Description:
As Glycine and NAC are amino acids, taking them with a large protein meal can lead to competition for absorption in the gut, potentially reducing their bioavailability and effectiveness. [class-derived from: class_pharmacology]
Actionable advice:
GlyNAC is best taken on an empty stomach, at least 1 hour before or 2 hours after a protein-rich meal.
Validation status:
validated_via_expert_review
Evidence tier:
tier_c
Evidence basis:
expert_review_verbatim
Evidence anchors:
Exact phrase from label:
N-Acetylcysteine - StatPearls
Label source:
Class inference: Glycine and NAC (N-acetylcysteine) are amino acid-based compounds absorbed via amino acid transporters (PEPT1, SLC transporters) in the small intestine; large protein meals competitively increase the amino acid load at these shared transporters, a pharmacokinetic mechanism well-established for amino acid supplements
Action type:
separate
Target id:
/class/antipsychotics
Target name:
Antipsychotic Medications
Severity:
moderate
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
The Glycine component may interfere with the mechanism of certain antipsychotic drugs, particularly clozapine, potentially reducing their effectiveness.
Actionable advice:
It is important to talk to a psychiatrist before using GlyNAC while taking antipsychotic medication, especially clozapine.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Augmentation strategy in the treatment of schizophrenia with the NMDA receptor co-agonist glycine has demonstrated significant improvement in patient symptoms. Interestingly, the therapeutic efficacy of glycine was more consistent among patients that were not co-administered clozapine suggesting that clozapine modulates glycine levels in brain.
Label source:
PubMed: Schizophrenia research (2004)
Source url:
Exact phrase from label:
However, these drugs have not shown clinical efficacy when added to clozapine, suggesting that the interactions of clozapine and the glycine site potentiators may be different from those of other antipsychotic drugs and the potentiators.
Label source:
PubMed: European archives of psychiatry and clinical neuroscience (2008)
Source url:
Exact phrase from label:
D-Cycloserine significantly worsened ratings of negative symptoms compared to placebo but did not significantly affect ratings of psychotic symptoms. CONCLUSIONS: The differing effects of D-cycloserine on negative symptoms when added to clozapine compared to conventional antipsychotics suggests that activation of the glycine recognition site may play a role in clozapine's efficacy for negative symptoms.
Label source:
PubMed: Biological psychiatry (1999)
Action type:
informational_none
Target id:
/class/antihypertensives
Target name:
Antihypertensive Medications
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
The NAC component may have a mild vasodilatory effect, which can add to the effects of prescribed blood pressure-lowering drugs, potentially causing dizziness or excessive hypotension.
Actionable advice:
Blood pressure should be monitored closely when starting GlyNAC alongside blood pressure medication.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Thiol supplementation with NAC improves human coronary and peripheral endothelium-dependent vasodilation.
Label source:
PubMed: Journal of the American College of Cardiology (2001)
Source url:
Exact phrase from label:
Symptomatic hypotension occurred frequently in the NTG/NAC group (7 vs 0 patients; P = 0.006).
Label source:
PubMed: European heart journal (1988)
Source url:
Exact phrase from label:
NAC accompanied with ACEI decreased the patients' systolic and diastolic blood pressure significantly; however, ACEI alone did not have any significant effects on blood pressure.
Label source:
PubMed: ARYA atherosclerosis (2015)
Action type:
monitor
Target id:
/condition/asthma-copd
Target name:
Asthma and COPD
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
In some individuals with reactive airway diseases, oral NAC can rarely trigger bronchospasm (constriction of airways), potentially worsening symptoms of asthma.
Actionable advice:
This is best used with caution, and it is important to talk to a doctor before taking GlyNAC for those with a history of asthma.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Exact phrase from label:
several cases of fatal bronchospasm have been reported in asthmatic patients after inhaled or intravenous N-acetylcysteine
Label source:
Primary literature: https://ekja.org/m/journal/view.php?number=5202
Action type:
informational_none
Target id:
/circadian/sleep
Target name:
Going to Sleep
Severity:
minor
Interaction type:
synergistic
Nature:
temporal
Temporal spacing:
Hours before target:
1.5
Hours after target:
0.5
Description:
The Glycine component is known to improve subjective sleep quality and reduce sleep latency, partly by lowering core body temperature, which signals the body to sleep.
Actionable advice:
Consider taking a dose of GlyNAC about 1 hour before bedtime to potentially enhance sleep quality.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
Oral administration of glycine to rats was found to induce a significant increase in the plasma and cerebrospinal fluid glycine concentrations and a significant decrease in the core body temperature associated with an increase in cutaneous blood flow. The decline in the core body temperature might be a mechanism underlying glycine's effect on sleep, as the onset of sleep is known to involve a decrease in the core body temperature.
Label source:
PubMed: Journal of pharmacological sciences (2012)
Source url:
Exact phrase from label:
In acute sleep disturbance, oral administration of glycine-induced non-rapid eye movement (REM) sleep and shortened NREM sleep latency with a simultaneous decrease in core temperature.
Label source:
PubMed: Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology (2015)
Source url:
Exact phrase from label:
While longer-term glycine administration improved sleep in healthy populations, these studies had small sample sizes with a high risk of bias.
Label source:
PubMed: GeroScience (2024)
Action type:
separate
Target id:
/condition/histamine-intolerance
Target name:
Histamine Intolerance
Severity:
minor
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
NAC may inhibit the diamine oxidase (DAO) enzyme, which is responsible for breaking down histamine in the gut, potentially worsening symptoms in sensitive individuals.
Actionable advice:
This is best used with caution or avoided in those with known histamine intolerance who experience worsening symptoms.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
drugs that release histamine or block DAO may provoke diarrhea, headache, rhinoconjunctival symptoms, asthma, hypotension, arrhythmia, urticaria, pruritus, flushing, and other conditions in patients with histamine intolerance
Label source:
Primary literature: Maintz & Novak Am J Clin Nutr 2007;85(5):1185 PMID 17490952
Action type:
avoid
Target id:
/intervention/activated-charcoal
Target name:
Activated Charcoal
Severity:
major
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
Activated charcoal is a potent adsorbent that will bind to NAC in the gut, preventing its absorption and rendering it completely ineffective.
Actionable advice:
GlyNAC and activated charcoal should be separated by at least 2 hours.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
N-acetylcysteine was adsorbed by activated charcoal, lending in vitro support to previous clinical of activated charcoal for NAC in biologic fluid was significantly greater than in nonbiologic fluid and has important clinical implications. Although some have advocated lavage to remove activated charcoal prior to the administration of NAC, the avid adsorption of NAC suggested that activated charcoal may not be justifiable for acetaminophen overdosage when NAC therapy is indicated.
Label source:
PubMed: Veterinary and human toxicology (1980)
Source url:
Exact phrase from label:
Results indicate that activated charcoal effectively adsorbs both methionine and N-acetylcysteine. Since these agents must be absorbed from the GI tract to prevent acetaminophen hepatotoxicity, concurrent administration of methionine or N-acetylcysteine and activated charcoal would be expected to markedly diminish their antidotal effectiveness.
Label source:
PubMed: Clinical toxicology (1981)
Source url:
Exact phrase from label:
A reduction in peak NAC level of 29% (P less than .02) and a reduction of total area under the curve (AUC) of 39% (P less than .001) was noted. Although it may be preferable to avoid completely the use of activated charcoal when using NAC to treat overdoses of acetaminophen, we recommend that if these agents are used together, doses of NAC be increased by 40% to compensate for the decreased oral absorption of NAC.
Label source:
PubMed: The American journal of emergency medicine (1987)
Action type:
separate