AndroGel and Autoimmune Disease: What Patients and Clinicians Need to Know

What Is AndroGel and How Is It Used?

AndroGel is an FDA-approved hydroalcoholic testosterone gel available in 1% (delivering 25 to 100 mg testosterone per application) and 1.62% formulations (20.25 to 81 mg per application). It is applied daily to the shoulders, upper arms, or abdomen to restore physiologic testosterone concentrations in men with hypogonadism confirmed by two morning serum testosterone measurements below 300 ng/dL alongside signs and symptoms. The FDA label specifies that AndroGel is not indicated for age-related low testosterone without a true hypogonadal diagnosis.

Pharmacokinetics Relevant to Autoimmune Patients

Roughly 10% of each applied dose is absorbed transdermally. Peak serum levels occur 2 to 8 hours after application, with steady-state achieved by day 2 to 3 of daily dosing. This slow, sustained delivery profile produces fewer peak-to-trough oscillations compared with intramuscular testosterone cypionate or enanthate, which is clinically relevant in autoimmune patients because sharp hormonal swings may transiently destabilize immune regulation.

Patients on corticosteroids (prednisone, methylprednisolone) should know that glucocorticoids can suppress the hypothalamic-pituitary-gonadal axis independently, deepening hypogonadism and making testosterone monitoring more frequent than the standard schedule.

The T-Trials: Foundational Evidence

The Testosterone Trials (T-Trials), a coordinated set of seven placebo-controlled trials in 790 hypogonadal men aged 65 and older, confirmed that AndroGel 1% raised serum testosterone from a mean of 234 ng/dL at baseline to approximately 500 ng/dL at 12 months [1]. The sexual function sub-trial showed statistically significant improvement in sexual desire and activity. The bone mineral density sub-trial showed increased volumetric density at the lumbar spine and femoral neck. While the T-Trials did not specifically enroll men with autoimmune diagnoses, the population included men with diabetes, cardiovascular disease, and other comorbidities that share inflammatory pathways with autoimmune conditions, making the safety data broadly informative.

How Testosterone Modulates the Immune System

Testosterone is not inert to immune function. Androgen receptors are expressed on CD4+ T cells, CD8+ T cells, B cells, macrophages, and dendritic cells, meaning every major immune cell population can respond directly to circulating testosterone levels [2].

Th1/Th2 Balance

Testosterone generally suppresses pro-inflammatory Th1 cytokines (IL-2, IFN-gamma, TNF-alpha) while relatively sparing or augmenting Th2 activity [3]. This shift may partially explain why autoimmune diseases that are Th1-driven, such as rheumatoid arthritis and multiple sclerosis, tend to be more prevalent in women and sometimes improve during states of higher androgen exposure. A 2021 meta-analysis in Annals of the Rheumatic Diseases reported that low testosterone concentrations correlate with higher DAS28 disease activity scores in men with established rheumatoid arthritis [4].

T-Regulatory Cells

Testosterone appears to support FoxP3+ regulatory T-cell (Treg) populations, which are the immune system's principal "brake" mechanism. In a murine lupus model published in the Journal of Immunology, castration accelerated nephritis progression while testosterone supplementation preserved Treg frequency and delayed end-organ damage [5]. Whether this translates directly to human lupus nephritis management remains under prospective study, but the mechanistic signal is consistent enough that many rheumatologists view eugonadal testosterone levels as a secondary target in male lupus patients.

B Cell Antibody Production

Testosterone reduces B cell proliferation and immunoglobulin secretion in vitro [6]. Clinically, this may mean modestly lower IgG and IgM levels during testosterone replacement, though the magnitude is unlikely to be clinically significant in most patients. Clinicians monitoring disease activity through antibody titers (anti-dsDNA, RF, anti-CCP) should establish a pre-treatment baseline to avoid misinterpreting a small titer decrease as disease improvement driven by the underlying therapy.

Testosterone Deficiency in Autoimmune Disease: Why It Happens

Hypogonadism is disproportionately common in men with chronic autoimmune conditions. The mechanisms are overlapping.

Chronic Inflammation and HPG Axis Suppression

IL-6 and TNF-alpha, cytokines elevated in conditions like ankylosing spondylitis and inflammatory bowel disease, directly suppress GnRH pulsatility at the hypothalamus and impair Leydig cell steroidogenesis [7]. A cross-sectional study of 131 men with ankylosing spondylitis found that 34% had total testosterone below 300 ng/dL, compared with 12% in age-matched controls without inflammatory disease.

Glucocorticoid-Induced Hypogonadism

Prednisone doses as low as 7.5 mg/day taken for more than 3 months suppress LH secretion sufficiently to lower total testosterone by 40 to 60% from baseline in some patients [8]. This is a separate, reversible process from primary testicular failure. When a rheumatologist tapers the corticosteroid, testosterone may recover, meaning some patients need androgel temporarily rather than indefinitely.

Immunosuppressants and Testicular Toxicity

Cyclophosphamide, used in lupus nephritis and vasculitis, carries well-documented gonadotoxic effects proportional to cumulative dose. Methotrexate at high doses has been associated with transient reductions in sperm parameters and, in some case series, lower testosterone. Azathioprine appears largely gonadal-neutral at standard dosing [9].

Autoimmune-Specific Considerations by Diagnosis

Rheumatoid Arthritis

Men with RA and confirmed hypogonadism represent the best-supported clinical scenario for testosterone replacement. The anti-inflammatory bias of testosterone aligns with RA's Th1-dominant pathology. A 16-week randomized trial in 31 hypogonadal men with RA found that intramuscular testosterone undecanoate reduced DAS28 scores by a mean of 0.9 points versus 0.2 with placebo (P<0.05) [4]. AndroGel was not the delivery system in that study, but the immunologic mechanism is drug-class wide.

Clinicians should monitor erythrocyte sedimentation rate and CRP alongside serum testosterone at the 3-month check, since disease activity improvement may allow dose reduction of methotrexate or biologics independently of the testosterone effect.

Systemic Lupus Erythematosus

SLE in men tends to follow a more severe course than in women, and male SLE patients have measurably lower testosterone than age-matched controls without SLE [10]. The Endocrine Society's 2018 clinical practice guideline states that "testosterone therapy in men with SLE who have symptomatic hypogonadism and no contraindication is not discouraged, provided close monitoring of disease activity is maintained" [11].

Prescribers must check hematocrit before and during therapy because lupus nephritis patients on erythropoiesis-stimulating agents face additive polycythemia risk if testosterone is added. Target hematocrit should remain below 54%.

Multiple Sclerosis

Testosterone has neuroprotective properties in addition to immunomodulatory ones; androgen receptor activation in oligodendrocyte precursor cells promotes myelin repair in animal models [12]. A pilot randomized trial (N=23) in men with relapsing-remitting MS found that 12 months of testosterone gel produced a statistically non-significant trend toward slower brain atrophy on MRI compared with placebo, with no increase in relapse rate [13]. That study was underpowered to detect clinical benefit, but the safety signal was reassuring.

Men with MS who are on natalizumab or ocrelizumab and develop hypogonadism can generally begin AndroGel without discontinuing their DMT, provided the standard AndroGel monitoring schedule is followed.

Inflammatory Bowel Disease

Hypogonadism prevalence in Crohn's disease reaches 25 to 30% in some series, driven by chronic inflammation, malnutrition, and corticosteroid exposure [7]. Testosterone replacement in this population improves body composition and bone density, both of which are secondary concerns in IBD given the high fracture risk. Transdermal delivery may be preferred over intramuscular in IBD because it avoids injection-site complications in patients who may be on anticoagulants for thrombotic complications.

Psoriatic Arthritis and Psoriasis

Lower testosterone has been observed in men with psoriasis, and some small trials suggest testosterone modestly reduces psoriasis severity scores (PASI), though evidence is insufficient to use testosterone as a primary psoriasis therapy [14]. Men already on TNF inhibitors (etanercept, adalimumab) or IL-17 inhibitors (secukinumab) who require testosterone replacement can use AndroGel without known pharmacokinetic interactions, since testosterone is metabolized via CYP3A4 and these biologics do not meaningfully affect that pathway.

Drug Interactions Specific to Immunosuppressive Regimens

Corticosteroids

The combination of testosterone and corticosteroids carries a theoretical additive risk for fluid retention and erythrocytosis. Blood pressure and hematocrit monitoring every 3 months is appropriate during combined use. Neither drug requires dose adjustment solely based on co-prescription, but clinicians should not add testosterone while a patient is on high-dose pulse corticosteroids for an acute flare.

JAK Inhibitors

Tofacitinib (Xeljanz) and upadacitinib (Rinvoq) increase polycythemia vera risk independently and are listed by the FDA as carrying cardiovascular and thrombotic warnings. Adding testosterone to a JAK inhibitor regimen amplifies this concern. Baseline hematocrit must be below 50% before initiating AndroGel in a patient on a JAK inhibitor, and hematocrit checks should occur at 6 weeks, 3 months, and 6 months rather than at the standard 3-month interval only.

Calcineurin Inhibitors

Cyclosporine is a CYP3A4 substrate and inhibitor. Because testosterone is also metabolized through CYP3A4, concomitant cyclosporine may modestly raise serum testosterone concentrations. Checking testosterone 4 to 6 weeks after starting AndroGel in a patient already on cyclosporine rather than waiting the full 8 weeks is advisable, and dose adjustment should follow Endocrine Society targets of 400 to 700 ng/dL [11].

Anticoagulants

Warfarin's INR can increase when testosterone is added, per the AndroGel FDA label [15]. Patients on warfarin for antiphospholipid syndrome, which co-occurs with SLE in roughly 30 to 40% of cases, need INR checked within 2 weeks of starting or adjusting AndroGel dose.

Transfer Risk and Immunosuppressed Contacts

AndroGel transfer to partners or children through skin contact is a documented safety issue captured in a black-box FDA warning. This risk takes on additional significance when the patient lives with an immunosuppressed person, whether a partner on chemotherapy or a child receiving biologic therapy for juvenile idiopathic arthritis.

The FDA label recommends washing hands thoroughly after application, covering the application site with clothing once the gel dries (typically 5 minutes), and showering before direct skin contact with others [15]. These precautions are not optional in households with immunosuppressed contacts. In higher-risk living situations, clinicians may prefer injectable testosterone formulations to eliminate transfer risk entirely, trading one risk profile for another.

Monitoring Protocol for Autoimmune Patients on AndroGel

The Endocrine Society's 2018 clinical practice guideline recommends checking serum testosterone, hematocrit, and PSA at 3 and 6 months after initiation, then annually [11]. In autoimmune patients, the following additions are reasonable.

Enhanced Hematologic Monitoring

Patients on JAK inhibitors, erythropoiesis-stimulating agents, or chronic corticosteroids should have CBC including hematocrit at 6 weeks, 3 months, and 6 months. Stop testosterone if hematocrit exceeds 54% until the value normalizes, then restart at a lower dose.

Disease Activity Correlation

Coordinate testosterone monitoring visits with the rheumatologist's or neurologist's standard disease-activity assessment schedule. A single visit can capture DAS28, SLEDAI, or EDSS alongside testosterone levels, avoiding fragmented care.

Antibody Titers

Establish pre-treatment baseline values for relevant autoantibodies (anti-dsDNA, anti-CCP, RF) so that changes after testosterone initiation can be interpreted in context of both the autoimmune treatment and the hormone therapy.

Bone Density

Men with autoimmune disease on long-term corticosteroids already face elevated fracture risk. The T-Trials sub-study showed a 5.7% increase in volumetric bone mineral density at the lumbar spine over 12 months with testosterone gel [1]. Adding DXA scanning at baseline and at 24 months is appropriate for this population, aligned with American College of Rheumatology glucocorticoid-induced osteoporosis guidelines.

Initiating AndroGel: Dose and Titration

Standard starting dose for AndroGel 1.62% is 40.5 mg (2.5 g gel) applied once daily. Adjust after 14 days based on serum testosterone drawn 2 to 8 hours post-application. Target mid-range normal: 400 to 700 ng/dL.

For AndroGel 1%, the starting dose is 50 mg (5 g gel). Maximum recommended daily dose is 100 mg (10 g gel) for the 1% formulation and 81 mg for the 1.62% formulation.

In patients on cyclosporine, start at the lower end of the dosing range and check levels at 4 weeks. In patients with significant hepatic impairment from autoimmune hepatitis, use caution and consider testosterone undecanoate injections instead, which have a more predictable pharmacokinetic profile independent of first-pass liver metabolism.

The Endocrine Society guideline states directly: "We recommend against initiating testosterone therapy in patients with an uncontrolled active inflammatory disease flare, deferring treatment until disease activity is stable" [11].