Clinical bottom line
Low-dose naltrexone (LDN) is a putative adjunctive therapy for chronic migraine management in primary care, with emerging evidence suggesting potential benefits in reducing headache frequency and severity, particularly in patients with comorbid chronic pain conditions. However, current data remain preliminary and largely observational, warranting cautious interpretation. LDN’s favorable safety profile and low cost may make it an option for select patients who have not responded adequately to standard migraine prophylaxis, but robust randomized controlled trials specifically targeting chronic migraine populations are needed before widespread adoption.
What the evidence shows
Low-dose naltrexone, typically dosed at 1–5 mg daily, is hypothesized to exert analgesic and anti-inflammatory effects through modulation of microglial activation and opioid receptor pathways (McKenzie et al., 2026). While most research on LDN has focused on chronic pain syndromes broadly, recent studies have begun to explore its role in chronic migraine.
A prospective observational pilot study by Figueiredo et al. (2024) evaluated LDN in patients with chronic migraine and comorbid fibromyalgia, reporting reductions in headache frequency and intensity over a 12-week period. Although limited by small sample size and lack of a control group, this study provides preliminary clinical signals supporting LDN’s potential benefit in this difficult-to-treat subgroup.
Systematic reviews and evaluations of LDN in chronic pain conditions, including neuropathic and regional pain syndromes, have noted modest improvements in pain scores and quality of life measures (Radi et al., 2023; Spargo et al., 2025). These findings suggest a plausible mechanistic rationale for LDN’s use in migraine, which shares overlapping neuroinflammatory pathways with other chronic pain disorders (Bostick Kirbie et al., 2019; McKenzie et al., 2026).
However, the evidence base remains limited by heterogeneity in study designs, patient populations, and dosing regimens. Most data derive from small observational cohorts or retrospective analyses rather than large-scale randomized controlled trials (Kennedy et al., 2025). Furthermore, the optimal dosing strategy and duration of therapy for migraine prevention have not been established.
Caveats and uncertainty
The current evidence for LDN in chronic migraine is hypothesis-generating rather than definitive. Key limitations include:
- Lack of randomized, placebo-controlled trials specifically in chronic migraine populations.
- Small sample sizes and short follow-up durations in existing studies.
- Potential confounding by comorbid chronic pain conditions in many cohorts.
- Uncertainty regarding the mechanism of action and patient subgroups most likely to benefit.
- Variability in dosing protocols and formulations used across studies.
- Limited data on long-term safety and tolerability in migraine patients.
Given these uncertainties, LDN should not replace established migraine prophylactic therapies but may be considered as an off-label adjunct in refractory cases after thorough discussion of the limited evidence and potential risks.
How this may change practice
For primary care clinicians managing patients with chronic migraine, particularly those with comorbid chronic pain syndromes or fibromyalgia, LDN may represent a low-risk adjunctive option when conventional therapies have failed or are contraindicated. Its low cost and favorable side effect profile make it an attractive candidate for individualized trials under close monitoring.
Clinicians should remain cautious and emphasize shared decision-making, clearly communicating the preliminary nature of the evidence. Monitoring for efficacy and adverse effects is essential, and LDN should be discontinued if no benefit is observed within a reasonable timeframe (e.g., 8–12 weeks).
Future integration of LDN into migraine management algorithms will depend on the results of ongoing and future randomized controlled trials that clarify its efficacy, optimal dosing, and patient selection criteria.