Rhodiola

Rhodiola rosea has plausible biochemical effects (stress-axis modulation, neurotransmitter effects, antioxidant/neuroprotective actions) and several clinical trials showing benefit for stress-related fatigue, mild–moderate depression, and burnout — but there are no large, high-quality randomized controlled trials specifically proving Rhodiola as an effective treatment for PTSD.

• Adaptogen effect / HPA-axis modulation: Rhodiola has been shown to reduce stress-response measures (including cortisol) and to modulate the hypothalamic–pituitary–adrenal (HPA) axis in several human trials and reviews — this is relevant to PTSD because dysregulated stress responses and cortisol signalling are a central pathophysiologic feature. BioMed Central
• Cell signalling & glucocorticoid receptor sensitivity: Some laboratory and clinical work suggests constituents of Rhodiola (e.g., rosavins, salidroside) influence stress-activated kinases (JNK) and glucocorticoid receptor sensitivity — a proposed mechanism for “restoring” normal cortisol signalling after chronic stress. ScienceDirect
• Monoamine / neurotransmitter effects: Preclinical and some clinical data indicate Rhodiola affects monoamine neurotransmitters (serotonin, norepinephrine, dopamine) and monoamine-oxidase activity; this provides a plausible antidepressant/anxiolytic action overlapping with some PTSD symptom mechanisms. ScienceDirect
• Anti-fatigue, cognitive and neuroprotective effects: Trials report improved mental performance, reduced fatigue, and better attention/concentration in stressed populations — useful for PTSD where cognitive fatigue and attention problems are common. MDPI

Summary: the biological actions of Rhodiola map onto processes implicated in PTSD (stress-axis dysregulation, mood/anxiety circuits, fatigue), which is why clinicians and herbalists consider it potentially helpful — but mapping ≠ definitive proof for PTSD specifically. MDPI

Typical extracts and standardization: Most clinical trials used standardized root extracts (commonly the SHR-5 or similar), standardized to a combination of rosavins (typically ~3%) and salidroside (~1%). When buying supplements, choose a product that states standardization to these marker compounds. ResearchGate

Common clinical doses used in trials:

• Low/short trials: 170 mg/day (e.g., Darbinyan et al. for fatigue). MDPI
• Many studies: ~340 mg/day (some trials used ~340 mg standardized extract daily). Dr. Tori Hudson, N.D.
• Other trials: single doses of 370 mg or 555 mg were tested for acute mental work capacity; some depression trials used 300–600 mg/day (often split dosing). MDPI

Typical duration in trials: 4 weeks to 12 weeks (many stress/fatigue studies 2–8 weeks; depression trials frequently 8–12 weeks). Improvements in fatigue/stress sometimes appeared within 2–4 weeks; antidepressant effects were assessed over 8–12 weeks. MDPI

When to take / administration tips (based on trial reports and safety notes):

• Most trials used oral capsules/tablets of standardized extract.
• Because Rhodiola can be mildly stimulating for some people, many clinicians advise taking the bulk of the dose earlier in the day (morning, or morning + early afternoon if split). (Trial designs and product inserts commonly reflect morning dosing.) MDPI

Typical practical regimen (examples used in trials):

• For stress/fatigue: 170–370 mg/day of SHR-5 extract for 2–8 weeks. MDPI
• For depressive symptoms (mild–moderate): studies used ~340 mg/day and higher doses up to ~600 mg/day across 8–12 weeks (some trials compared low vs high dose). ScienceDirect

Phytomedicine randomized trial (Mao et al., 2015) — proof-of-concept RCT comparing Rhodiola (standardized extract ~340 mg/day) vs sertraline vs placebo in mild–moderate Major Depressive Disorder (12 weeks, n≈57). Result: rhodiola produced clinically meaningful symptom reductions and was generally better tolerated than sertraline; however, the trial was small and was not specifically a PTSD population. Europe PMC

Larger clinical trial programs & acute dosing trials (Shevtsov, Darbinyan, etc.) — multiple randomized, double-blind studies showed reduced fatigue, improved mental performance, and reduced stress symptoms with standardized SHR-5 extracts at doses in the ~170–555 mg range. (Examples collected in reviews.) MDPI+1

Systematic reviews / narrative reviews:

• BMC Complementary Medicine systematic review (fatigue/stress) — summarized randomized trials showing benefit for physical and mental fatigue and generally good tolerability, while noting the heterogeneity of trials and the need for larger studies. BioMed Central
• MDPI review (2022) — an up-to-date review of clinical efficacy and mechanisms, summarizing many human trials and concluding there is evidence of benefit in stress-related conditions and some depressive symptoms, but that study quality and sizes vary. MDPI
• Stress-management review (2017) — concluded trials are promising for chronic stress, fatigue and burnout but called for larger randomized trials. Taylor & Francis Online

Conclusion about PTSD specifically: authoritative sources and repositories (e.g., PTSD clinical trial registries and systematic reviews) indicate limited/absent direct evidence for PTSD; most evidence is indirect — i.e., improvement in anxiety, depression, fatigue, and HPA-axis measures that are relevant to PTSD but not a direct PTSD RCT. If you need treatment specifically for PTSD symptoms (re-experiencing, hypervigilance, avoidance, severe sleep/nightmares), evidence-based PTSD treatments (trauma-focused psychotherapy, SSRIs approved for PTSD where appropriate) have stronger direct evidence. PTSD VA