Low-Dose Naltrexone International Purchase Legalities: What You Need to Know

Is there an approved low-dose naltrexone product?

No. FDA has approved naltrexone as 50 mg tablets and as a 380 mg monthly gluteal injection [4][5]. LDN means 0.5 to 6 mg a day, most often 4.5 mg, prescribed off-label and supplied mainly as a compounded capsule or liquid [1]. A 2026 review of 105 studies, 15 of them randomized, calls the 4.5 mg dose empirically derived rather than evidence-based and notes that inconsistencies in compounded formulations add uncertainty [1].

What FDA says about compounded drugs and online buying

Compounded drugs are not FDA-approved, and FDA does not verify their safety, effectiveness or quality before they are marketed [6]. Poor compounding practices can leave a product contaminated or with too much or too little active ingredient [6]. People buying compounded drugs online may not know who made the product or whether the compounder is properly licensed and regulated [6]. Under the patient-specific-prescription pathway, federal law requires a valid prescription; FDA also describes outsourcing facilities that may distribute compounded drugs in response to a health-care-provider order [7].

What happens at the U.S. border

FDA Import Alert 66-41 covers unapproved new drugs, which FDA says have not been reviewed for safety or effectiveness [2]. It allows field divisions to detain identified products from firms on its red list without physical examination [2]. For personal-importation shipments, it directs staff to follow the Regulatory Procedures Manual guidance. It says commercial or promotional shipments, and products subject to detention without examination, are generally not amenable to enforcement discretion [2].

Naltrexone is not named on FDA's list of bulk drug substances that may present significant safety risks in compounding (page current as of 04/22/2026) [3]. That does not make an imported finished product FDA-approved.

Opioid precautions still apply

The naltrexone labels were written for 50 mg tablets and 380 mg injections and give no guidance on LDN doses [1][4]. They list as contraindications patients receiving opioid analgesics and patients currently dependent on opioids, including those maintained on methadone or buprenorphine. The opioid-analgesic contraindication is written without any dose exception [4][5]. In an opioid-dependent person, naltrexone can precipitate withdrawal severe enough to require hospitalization [4]. The labels recommend a minimum of 7 to 10 opioid-free days beforehand [4][5].

The domestic route

HealthRX.com offers low-dose naltrexone by prescription.