Shilajit: Testosterone, Performance and Safety Evidence

Table of contents

• Evidence summary
• What shilajit is
• Forms and preparations
• Proposed mechanisms
• The hype vs the evidence
• Benefits by claim
• Claims and limits
• Safety findings and gaps
• Medicines and evidence gaps
• Who should seek advice first
• Studied protocols, not a recommended dose
• How preclinical evidence is used
• Funding, conflicts and source roles
• Frequently asked questions
• Sources and funding notes

What shilajit is

Shilajit is a complex rock exudate used in traditional Ayurvedic preparations. It can contain organic substances and minerals, including heavy metals; composition depends on the material and processing (OPSS description). The clinical preparations discussed here are specific extracts or processed resin, not every product sold as shilajit. Marker percentages and a purification label do not establish a product’s contaminant content or clinical benefit.

The reviewed studies include a Natreon-funded hormone trial, a Natreon-funded exercise trial and an uncontrolled manufacturer-linked resin pilot. Their endpoints and populations differ (Pandit; Keller; Yadav); they cannot be combined into proof of broad male vitality.

Forms and preparations

Preparation and dosage form are different. A capsule can contain a particular extract or another powder; a resin can be processed and standardised. The examples below do not rank efficacy or safety.

Proposed mechanisms

Fulvic substances and dibenzo-α-pyrone-related compounds occur in the studied extracts. Their proposed antioxidant or mitochondrial roles are mechanistic explanations, not established treatment effects. Pandit measured circulating hormones and interpreted them in terms of endogenous steroid production; the trial did not directly measure a cellular steroidogenic mechanism (original Methods and Discussion).

The reviewed hormone and exercise trials do not establish a human mitochondrial mechanism. Keller discusses animal mitochondrial findings as an explanation, but measured muscular performance and hydroxyproline instead (hormone endpoints; exercise Methods and Discussion).

The hype vs the evidence

The reported hormone and exercise findings concern different populations and preparations. They do not establish a universal energy, libido or sexual-function benefit.

• The 90-day hormone trial assigned 96 men aged 45–55 to PrimaVie capsules or placebo, 250 mg twice daily after major meals. It analysed 75 completers and reported higher total/free testosterone and DHEAS at day 90; baseline hormone imbalance and the exclusion of 21 discontinuers limit interpretation. Natreon financial support is acknowledged. It does not establish symptomatic treatment of clinical testosterone deficiency or an effect for all men.
• The 28-day TruBlk pilot reported leg-press strength +12.94%, FSS −32.40% and CRP −25.35% from baseline in 25 men. Aerobic capacity was estimated rather than measured by gas exchange. There was no control group or multiplicity adjustment; total testosterone did not significantly change. Four authors have maker affiliations. These before/after changes cannot establish what shilajit caused.

The testosterone signal comes from a Natreon-funded trial (original acknowledgement). The funding requires disclosure and scrutiny; it does not by itself disprove the measured result or establish an independently replicated benefit. Broad vitality claims extend beyond its efficacy endpoints.

Benefits by claim

Testosterone and hormonal markers

Pandit used Natreon’s PrimaVie and acknowledged Natreon financial support (original paper). The analysis excluded 21 discontinuers, and baseline total/free testosterone differed between groups; no baseline-adjusted efficacy model is described. ADAM questions about libido, energy and erections were used for screening, but longitudinal clinical symptom improvement was not demonstrated. The reported hormone signal does not establish a proven mechanism, treatment for low-testosterone symptoms or independent replication.

Energy, fatigue, and physical performance

Keller randomised 63 young, recreationally active men to PrimaVie 250 mg/day, 500 mg/day or placebo for eight weeks (original exercise trial). In the full sample, fatigue-related isometric strength decline was lower at 500 mg than 250 mg; the positive placebo comparison was limited to the upper baseline-strength half, ten men per arm. Pre-fatigue strength did not improve. Multiple outcomes and median-split analyses limit confidence; Natreon funded the study. The separate resin pilot was uncontrolled. Neither establishes a general daily-energy benefit.

General "vitality" and libido

The reviewed protocols do not establish a libido, mood or broad vitality treatment. Pandit used ADAM libido/energy/erection questions at screening and reported hormone efficacy results; it did not demonstrate longitudinal symptom improvement (original screening and Results). Hormonal changes alone cannot establish a clinical sexual-function benefit.

Claims and limits

Safety findings and gaps

Keller reported no adverse events over eight weeks (original Results). The resin pilot reported mild, self-limiting events in seven of 25 men (28%), including one possibly related rash; no serious events or discontinuations were reported (Table 6). These samples cannot quantify rare or long-term harms. OPSS separately lists suspected serious reactions and contaminant concerns; suspicion is not proof of cause or a frequency estimate (guidance).

Medicines and evidence gaps

Who should seek advice first

• People considering a product without clear composition and reliable contaminant results: OPSS says laboratory testing is needed to establish the actual content. Neither “raw” nor “purified” is a substitute for that information (guidance).
• Pregnant or breastfeeding people: the reviewed clinical trials do not establish safety in these populations (male hormone trial; male pilot). FDA warns that heavy metals can transfer into breast milk if a mother has an elevated body burden (exposure warning); this is not a quantified shilajit pregnancy risk.
• Children: adult trials do not establish paediatric safety, and FDA warns that harmful metal exposures can make adults and children seriously ill (adult exercise trial; FDA warning).
• People with iron-overload or other conditions requiring mineral restriction: discuss the product’s measured composition with the treating clinician; these sources do not prove every shilajit raises iron (composition guidance; supplement advice).
• People taking medicines: the reviewed studies excluded several diseases and drug exposures. Their results cannot establish safety of concurrent use, and FDA advises professional discussion before using supplements (hormone exclusions; pilot eligibility; FDA guidance).
• People seeking treatment for low testosterone, persistent fatigue or libido problems: the reviewed hormone result does not establish symptom treatment or replace medical assessment (original outcomes).

Studied protocols, not a recommended dose

How preclinical evidence is used

Preclinical findings can suggest mechanisms but cannot establish a human treatment effect. The reviewed hormone and exercise protocols did not directly demonstrate the proposed mitochondrial pathway (Pandit; Keller). Their reported outcomes are described as commercial-context evidence, with design limits and funding disclosed; lack of independent confirmation does not prove a null effect.

Funding, conflicts and source roles

Frequently asked questions

Does shilajit actually raise testosterone?

The Natreon-funded 90-day trial reported higher testosterone/DHEAS with PrimaVie capsules in men aged 45–55. It analysed 75 of 96 randomised men, had baseline testosterone differences and did not demonstrate clinical symptom improvement. The paper identifies a Natreon preparation and financial support; it does not itemise whether the product was donated or purchased. Independent replication and broader vitality benefit are not established by this report.

Is shilajit safe to take?

No cited study establishes safety of every product or long-term use. Keller reported no events over eight weeks; the 28-day resin pilot reported mild events in seven of 25 men and no serious events (Keller; pilot). OPSS separately lists suspected serious reactions and contaminant concerns, without incidence or proven ingredient causation (guidance). A purity label alone cannot resolve those questions.

What is the difference between raw shilajit and PrimaVie/Natreon-type products?

PrimaVie in Pandit was a specified purified extract delivered in capsules, with minimum marker specifications. This differs from unspecified raw material or a generic resin label, but the trial did not compare their safety (original preparation). The TruBlk pilot used a processed, standardised resin, not unpurified rock material (pilot preparation). Laboratory measurements remain necessary to establish a retail product’s actual contents (OPSS).

Does shilajit boost energy and athletic performance?

The controlled exercise trial was Natreon funded. Its positive placebo comparison concerned fatigue-related isometric strength loss in the stronger baseline subgroup, not general pre-fatigue strength or daily energy (Keller Results). The manufacturer-linked resin pilot had only before/after comparisons, and its total testosterone change was not significant (pilot Results). These findings do not establish an independently replicated general energy benefit.

Does stacking shilajit with Tongkat Ali make it more effective?

The reviewed trials did not test shilajit with Tongkat Ali. An ingredient-alone hormone or exercise finding does not establish amplified effects or safety of the combination (hormone protocol; exercise protocol).

Is shilajit FDA-approved?

FDA says there are no approved Ayurvedic products; its contaminated-products warning does not establish shilajit efficacy or a product-wide safety rate (FDA warning). Dietary supplements follow a different framework from approved drugs, and FDA generally does not approve them before sale (supplement guidance). Neither a trial nor a branded extract label is blanket FDA approval.

Sources and funding notes

• Pandit 2016 original — PrimaVie capsule hormone trial; Natreon support, 96 randomised/75 completers, baseline imbalance and symptom-outcome limits.
• Yadav 2026 original — 25-man processed-resin pilot; commercial-author ties, no control and generic no-support declaration. Mild events in seven participants; no serious events reported.
• HerbVerdict scorecard — secondary editorial summary, self-declared no brand ties; funding/ownership not independently cleared and some trial details conflict with originals.
• OPSS shilajit guidance — government ingredient guidance on suspected adverse effects, limited efficacy evidence and actual-content testing; no comparative form risk rate.
• FDA Ayurvedic-products warning — certain contaminated products and harmful exposure, not a shilajit-specific safety survey.
• Kerry 2022 acquisition announcement — commercial ownership context for Natreon/PrimaVie, not the sponsor identity of the earlier hormone and exercise trials.
• Keller 2019 original — 63-man, eight-week exercise trial; Natreon funding/no competing interests declared. Positive placebo comparison in stronger subgroup, no general pre-fatigue strength benefit.