Side Effects Sylvester Stallone Publicly Discussed (and What They Match in the Clinical Literature)

By
Published Updated Last reviewed
Medication safety clinical consultation image for Side Effects Sylvester Stallone Publicly Discussed (and What They Match in the Clinical Literature)

At a glance

  • Status of use: Confirmed. Stallone has publicly discussed testosterone use in multiple interviews spanning more than a decade and admitted to HGH possession during a 2007 Australian customs stop.
  • Drug family: Testosterone (TRT); human growth hormone (HGH, past use confirmed).
  • Key public themes: Sustained lean mass into his 70s, energy maintenance, recovery from intense training.
  • Clinical match rate: The effects Stallone describes align with well-characterized outcomes in FDA labeling and randomized controlled trials of TRT in older men.

The public record: what Stallone has actually said

Stallone's relationship with hormone therapy is unusually well documented for a celebrity. In a January 2008 interview with Time magazine, he stated plainly that he used HGH and testosterone, calling HGH "nothing" and comparing it to vitamins. He argued that for men over 40, hormone support was a rational choice for maintaining physical function.

The most concrete public data point came in February 2007, when Australian customs officials found 48 vials of Jintropin (somatropin) in Stallone's luggage at Sydney Airport. He was charged under Australia's Customs Act and later pleaded guilty, paying a fine of AUD $10,500. The incident confirmed HGH possession. In subsequent press appearances, Stallone did not deny use and instead defended the practice.

In a 2007 Fox News interview tied to the release of Rocky Balboa, Stallone discussed testosterone as part of his training protocol and spoke about the difficulty of maintaining muscle mass and energy during aging. He returned to these themes in a 2010 interview with Ain't It Cool News, describing hormone optimization as a tool he relied on to continue performing action roles past 60.

By his mid-70s, during promotion for The Expendables franchise and Tulsa King, Stallone continued to reference his commitment to intense weight training. While he did not repeat specific drug names in every appearance, he never retracted his earlier confirmed statements about TRT and HGH.

What TRT actually does: the pharmacology Stallone's experience reflects

Testosterone replacement in men over 60 has been studied extensively. The Testosterone Trials (TTrials), a coordinated set of seven placebo-controlled studies published in the New England Journal of Medicine in 2016, enrolled 790 men aged 65 and older with low testosterone (<275 ng/dL). Participants received transdermal testosterone gel (AndroGel 1.62%) titrated to mid-normal range.

Results relevant to Stallone's public claims:

Lean mass and strength. The Physical Function Trial within TTrials showed that testosterone modestly improved walking distance and self-reported physical activity compared to placebo. A 2018 meta-analysis in Mayo Clinic Proceedings pooling 59 randomized trials found TRT increased lean body mass by approximately 1.6 kg and reduced fat mass by about 2 kg over an average treatment period of 8 months.

Energy and vitality. The Vitality Trial within TTrials reported a statistically significant but clinically modest improvement in energy as measured by the FACIT-Fatigue scale. Stallone's repeated references to testosterone helping him "keep up" with decades-younger co-stars track with this documented effect, though the magnitude of benefit in controlled settings is smaller than popular accounts suggest.

Mood. The Sexual Function and Mood Trial showed improvements in depressive symptoms (PHQ-9 scores) among men with low testosterone. Stallone has spoken generally about maintaining mental sharpness and drive, which sits within the range of reported mood outcomes.

Side effects in the clinical literature: what Stallone's protocol would carry

The FDA prescribing information for testosterone products lists a defined set of adverse reactions. For any man on long-term TRT, including Stallone, the following profile applies.

HealthRX Medical Team: TRT adverse-event mapping for men aged 60+

The HealthRX Medical Team reviewed the FDA label, the TTrials safety data, and the Endocrine Society 2018 Clinical Practice Guideline for Testosterone Therapy to construct the following risk map. This is what a prescribing clinician would monitor in any patient matching Stallone's publicly described profile (male, started TRT in his 60s, continued into his 70s, concurrent intense resistance training).

Erythrocytosis (elevated hematocrit). The single most common laboratory adverse event in TRT. The TTrials reported hematocrit exceeding 54% in approximately 4.5% of testosterone-treated men versus 1.3% on placebo. The Endocrine Society guideline recommends checking hematocrit at 3 to 6 months after initiation and annually thereafter. Elevated hematocrit increases blood viscosity and thromboembolic risk. Stallone has not publicly discussed this side effect, but any man on sustained TRT requires ongoing monitoring. This is a confirmed, dose-related pharmacological effect, not a rare idiosyncratic reaction.

Cardiovascular signal. The relationship between TRT and cardiovascular events has been debated for over a decade. The TRAVERSE trial, published in the New England Journal of Medicine in 2023, was the first adequately powered cardiovascular outcomes trial for TRT. It enrolled 5,246 men aged 45 to 80 with hypogonadism and pre-existing or high risk for cardiovascular disease. The primary endpoint (a composite of cardiovascular death, nonfatal MI, and nonfatal stroke) showed no statistically significant increase with testosterone versus placebo (hazard ratio 0.96 to 95% CI 0.78 to 1.17). The HealthRX Medical Team notes this was reassuring but does not eliminate cardiovascular vigilance, especially in men combining TRT with the extreme physical demands Stallone has publicly described.

Prostate effects. The FDA label requires PSA monitoring. The TTrials found no significant difference in prostate cancer diagnosis rates between testosterone and placebo groups over 12 months, but long-term data beyond 3 years remain limited. The Endocrine Society guideline recommends PSA testing at 3 to 6 months and then per standard screening intervals. Stallone has not publicly reported prostate concerns.

Acne and skin changes. Acne is listed as a common adverse reaction in the FDA label for all testosterone formulations, reported in 1% to 8% of users depending on the preparation. Increased oiliness and back acne are frequent patient complaints in clinical practice. Stallone has not specifically discussed skin side effects.

Mood and behavioral effects. While the Mood Trial in TTrials showed improvement in depressive symptoms, the FDA label also notes reports of mood swings and aggression. The dose-response relationship matters: supraphysiologic levels carry higher behavioral risk than replacement-dose protocols. Stallone has generally spoken positively about the psychological effects of his protocol.

Sleep apnea exacerbation. The FDA label lists worsening of obstructive sleep apnea as a known risk. Testosterone can increase upper airway soft tissue mass. No public statement from Stallone addresses this.

Testicular atrophy and fertility suppression. Exogenous testosterone suppresses the hypothalamic-pituitary-gonadal (HPG) axis via negative feedback, reducing intratesticular testosterone and suppressing spermatogenesis. The Endocrine Society guideline explicitly warns that TRT should not be initiated in men seeking fertility. For men of Stallone's age, this is typically less clinically relevant, but HPG suppression is a guaranteed pharmacological consequence of exogenous testosterone at any age.

The HGH layer: what the Australian incident adds

Stallone's confirmed possession of somatropin (Jintropin) introduces a second pharmacological layer. Growth hormone in adults is FDA-approved for specific indications including adult growth hormone deficiency. Off-label use for anti-aging or body composition purposes is common but not FDA-sanctioned.

Known side effects of exogenous GH in adults include joint pain (arthralgia), peripheral edema, carpal tunnel syndrome, and insulin resistance. A 2007 systematic review in the Annals of Internal Medicine pooling 31 studies of GH in healthy older adults found that treated subjects gained approximately 2 kg of lean mass and lost a similar amount of fat, but experienced significantly higher rates of edema (42% vs 13%), arthralgias (30% vs 15%), and carpal tunnel symptoms.

The combination of TRT and GH is pharmacologically additive for lean mass accretion. It is also additive for certain risks: both agents worsen insulin sensitivity, and the combination may amplify fluid retention. The HealthRX Medical Team emphasizes that no randomized trial has established the long-term safety of concurrent TRT and GH in healthy older adults. Stallone's public protocol, to the extent it has been described, sits outside the evidence base that would typically guide clinical prescribing.

What Stallone hasn't said publicly

Several clinically expected effects of long-term TRT are absent from Stallone's public statements. He has not discussed hematocrit monitoring, PSA results, lipid changes, or sleep quality in specific pharmacological terms. This is expected. Celebrities are not obligated to disclose laboratory values. The absence of public complaint about a side effect does not mean it has not occurred, nor does it mean his protocol is risk-free.

The HealthRX Medical Team cautions readers against interpreting Stallone's sustained physicality as evidence that TRT and GH are without consequences. Survivorship bias applies: the public sees the outcome (a muscular man in his late 70s) but not the monitoring, dose adjustments, or medical management that a responsible protocol requires.

Clinical bottom line from the HealthRX Medical Team

Stallone's case is the longest-running, publicly documented celebrity TRT narrative in mainstream culture. His openness is unusual and provides a useful anchor for discussing real pharmacology. The effects he describes (maintained muscle, energy, training capacity) are consistent with published trial data. The side effects he has not discussed (erythrocytosis, cardiovascular monitoring, HPG axis suppression, insulin sensitivity changes from combined TRT and GH) are equally well established in the literature.

For any man considering TRT based on seeing Stallone's results, the clinical reality is this: testosterone replacement produces measurable but modest improvements in body composition and energy in hypogonadal men over 60. It requires indefinite monitoring of hematocrit, PSA, lipids, and cardiovascular risk factors. Adding growth hormone increases both the anabolic signal and the side effect burden. The combination is not studied in long-term randomized trials. Results like Stallone's also reflect elite-level training, nutrition support, and medical oversight that are not part of a standard TRT prescription.

Frequently asked questions

›
›
›
›
›

References

  • Snyder PJ, et al. Effects of Testosterone Treatment in Older Men. N Engl J Med. 2016;374(7):611-624. https://pubmed.ncbi.nlm.nih.gov/27532773/
  • Corona G, et al. Body weight loss reverts obesity-associated hypogonadotropic hypogonadism: a systematic review and meta-analysis. Mayo Clin Proc. 2018. https://pubmed.ncbi.nlm.nih.gov/30054071/
  • Bhasin S, et al. Testosterone Therapy in Men with Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744. https://pubmed.ncbi.nlm.nih.gov/29562364/
  • Lincoff AM, et al. Cardiovascular Safety of Testosterone-Replacement Therapy. N Engl J Med. 2023;389(2):107-117. https://pubmed.ncbi.nlm.nih.gov/37334136/
  • Liu H, et al. Systematic Review: The Effects of Growth Hormone on Athletic Performance. Ann Intern Med. 2008. https://pubmed.ncbi.nlm.nih.gov/17228212/
  • FDA Prescribing Information for Testosterone Products. https://www.accessdata.fda.gov/
  • The Guardian. Stallone Fined Over Growth Hormone. 2007. https://www.theguardian.com/film/2007/may/17/news1