Effectiveness and Safety of OTC Supplements for Mild Anxiety in Young Adults Compared With First-Line Pharmacologic Therapies: A Comparative Literature Review
DOI: Pending DOI
Synopsis
This literature review evaluates the effectiveness and safety of commonly used over-the-counter (OTC) supplements for mild anxiety in young adults compared with first-line pharmacologic therapies, including SSRIs and SNRIs. Supplements reviewed included L-theanine, magnesium, ashwagandha, and kava. Current evidence suggests that ashwagandha demonstrates the most consistent anxiolytic effects, while magnesium and L-theanine show more variable benefits. Kava demonstrated moderate efficacy but remains limited by safety concerns, particularly hepatotoxicity. Although OTC supplements may provide benefit for mild or situational anxiety, SSRIs and SNRIs remain the most evidence-based treatments for moderate to severe anxiety disorders.
Background
Anxiety disorders are highly prevalent among young adults and are often associated with academic stress, social pressures, and major lifestyle transitions that negatively affect emotional well-being and daily functioning. While first-line pharmacologic treatments, including selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), remain the standard evidence-based therapies for anxiety disorders, many young adults seek over-the-counter (OTC) supplements because of accessibility, cost, treatment preferences, and concerns regarding medication side effects. Common OTC supplements including L-theanine, magnesium, ashwagandha, and kava have gained increasing attention for their potential anxiolytic properties and perceived “natural” approach to anxiety management. However, evidence regarding their effectiveness and safety remains variable and inconsistent across studies. This literature review evaluates the current evidence regarding commonly used OTC supplements for mild anxiety in young adults compared with established first-line pharmacologic therapies, with a focus on effectiveness, safety, and potential clinical applications.
Methods
A narrative literature review was conducted to evaluate the effectiveness and safety of commonly used over-the-counter (OTC) supplements for anxiety compared with first-line pharmacologic treatments. Literature searches were performed using PubMed, Google Scholar, and ScienceDirect. Search terms included combinations of “anxiety,” “OTC supplements,” “L-theanine,” “magnesium,” “ashwagandha,” “kava,” “SSRIs,” and “SNRIs.” Randomized controlled trials, systematic reviews, meta-analyses, and observational studies published in peer-reviewed journals were included. Studies were excluded if they lacked anxiety-related outcomes, sufficient methodological detail, or English-language availability. Approximately 30 studies were initially screened, with 13 references ultimately included based on relevance, methodological quality, and applicability to anxiety management. Due to heterogeneity in study populations, supplement formulations, interventions, and outcome measures, findings were synthesized using a narrative review approach rather than a formal meta-analysis.
Results
Among OTC supplements reviewed, ashwagandha demonstrated the most consistent evidence supporting reductions in stress and anxiety symptoms. Multiple randomized controlled trials reported significant improvements in anxiety scores, perceived stress levels, and stress-related biomarkers including cortisol. Magnesium supplementation demonstrated potential anxiolytic benefits primarily in individuals with stress-related symptoms or low baseline magnesium levels, although findings across studies were inconsistent because of variability in study design, dosing, and outcome measures. L-theanine demonstrated favorable safety and modest improvements in stress-related symptoms, relaxation, and sleep quality; however, evidence supporting its efficacy in clinically significant anxiety disorders remained limited. Kava demonstrated moderate anxiolytic effects in some studies, particularly in individuals with mild to moderate anxiety, but concerns regarding hepatotoxicity and inconsistent efficacy findings limited its clinical reliability and long-term use.
In contrast, SSRIs and SNRIs consistently demonstrated stronger and more reliable efficacy across moderate to severe anxiety disorders and remain the most evidence-based pharmacologic treatments for generalized anxiety disorder. Medications including sertraline, escitalopram, venlafaxine, and duloxetine showed significant reductions in anxiety symptoms across multiple randomized controlled trials and meta-analyses. However, these medications were associated with adverse effects including gastrointestinal disturbances, insomnia, sexual dysfunction, and rare but serious risks such as serotonin syndrome and increased suicidality in younger individuals.
Overall, OTC supplements appeared most beneficial for mild, situational, or stress-related anxiety and may serve as adjunctive rather than replacement therapies for first-line pharmacologic treatment. Evidence quality for OTC supplements remained limited by small sample sizes, short intervention durations, variability in supplement formulations, and reliance on self-reported outcome measures.
Discussion
Current evidence suggests that OTC supplements may provide modest benefit in the management of mild, situational, or stress-related anxiety, particularly among young adults seeking accessible or nonprescription approaches to symptom management. Among the supplements reviewed, ashwagandha demonstrated the most consistent evidence of anxiolytic benefit, while magnesium and L-theanine showed more variable or limited effects. Kava demonstrated some efficacy but remains limited by important safety concerns, particularly hepatotoxicity. Despite increasing interest in OTC alternatives, SSRIs and SNRIs continue to demonstrate the strongest and most reliable evidence for the treatment of moderate to severe anxiety disorders.
Importantly, OTC supplements should generally be considered complementary or adjunctive options rather than replacements for evidence-based pharmacologic therapies when clinically indicated. Current evidence remains limited by study heterogeneity, small sample sizes, variability in supplement formulations, and reliance on self-reported outcomes. Additional large-scale, well-designed studies focused on young adult populations are needed to better evaluate the long-term efficacy, safety, and clinical role of OTC supplements in anxiety management.
Disclosures
The authors report no financial relationships, conflicts of interest, commercial affiliations, or industry funding related to the content of this work. Neither the authors nor their spouses/domestic partners have financial interests in any OTC supplement manufacturers, pharmaceutical companies, or commercial entities discussed in this review.
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