Can I Take Saw Palmetto with Testosterone Enanthate?

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Is there a known interaction between saw palmetto and testosterone enanthate?

A 2009 systematic review of herb-drug interactions, which identified 128 case reports or case series and 80 clinical trials across seven popular herbs, reported no interactions for saw palmetto (Serenoa repens) [1]. A 2017 review in American Family Physician placed saw palmetto among supplements with a low likelihood of drug interactions with most medications, with certain caveats [11].

Testosterone enanthate has its own named interactions on the label: oral anticoagulants (C-17 substituted testosterone derivatives have been reported to decrease the anticoagulant requirement, and patients on oral anticoagulants need close monitoring especially when androgens are started or stopped), insulin and diabetes drugs (androgens may lower blood glucose and insulin requirements), ACTH and corticosteroids (enhanced tendency toward edema), and oxyphenbutazone (elevated serum levels may result) [2]. Saw palmetto is not among them.

Does saw palmetto lower DHT the way finasteride does?

In serum, the human data show no effect of the saw palmetto extract that was tested.

In a 1-week randomized, open, placebo-controlled study of 32 healthy men aged 20 to 30, finasteride 5 mg reduced serum DHT by 65% after a single dose and by 52% to 60% with repeated daily doses, while Permixon had no effect on serum DHT, the same as placebo [3].

Prostate tissue is a different measurement. In a 6-month randomized trial of 40 men with benign prostatic hyperplasia, a saw palmetto herbal blend lowered DHT measured in prostate biopsy cores by 32%, from 6.49 to 4.40 ng/g (P<0.005), with no significant change on placebo [4]. That is a small, local, tissue-level finding in a small trial. It does not show a drop in the serum DHT a blood test measures.

For comparison, the Proscar label states that finasteride 5 mg daily reduces serum DHT by approximately 70% with continued treatment [12].

Will saw palmetto hide a rising PSA on testosterone enanthate?

The masking concern assumes saw palmetto lowers PSA. It did not in STEP or CAMUS.

CAMUS enrolled 369 men aged 45 or older. Those assigned to saw palmetto took 320 mg/day for 24 weeks, then 640 mg/day for 24 weeks, then 960 mg/day for 24 weeks; the others received placebo. Mean PSA change was +0.23 ng/mL with saw palmetto versus +0.16 ng/mL with placebo (p=0.50) [6]. In STEP, 225 men took 160 mg twice daily or placebo for a year, with no difference in PSA between groups [5]. The National Center for Complementary and Integrative Health states that saw palmetto does not appear to affect PSA readings, even at higher-than-usual amounts [9].

Finasteride is the drug in this area that does move PSA. Its label states that it reduces serum PSA by about 50% within six months, that a new PSA baseline should be set at least six months after starting, and that any confirmed rise from the lowest value while on finasteride may signal prostate cancer and should be evaluated even if the number looks normal for an untreated man [12].

The testosterone enanthate label's own prostate language is a contraindication in men with known or suspected carcinoma of the prostate, and a note that geriatric patients treated with androgens may be at increased risk for prostatic hypertrophy and prostatic carcinoma [2].

Does saw palmetto increase bleeding risk on testosterone injections?

The bleeding signal for saw palmetto rests on one case report. A man taking saw palmetto had severe bleeding during an operation with a prolonged bleeding time that normalized a few days after he stopped the herb [7].

The controlled evidence is quieter. In a study of 75 men scheduled for transurethral resection of the prostate, 27 took saw palmetto 160 mg/day, 27 took dutasteride 5 mg/day and 21 were controls, all for 5 weeks before surgery. Total blood loss, blood loss per unit of resected tissue, hemoglobin change and microvessel density did not differ significantly between the groups [8]. No study of saw palmetto with warfarin or other anticoagulants was found.

The bleeding-related interaction the enanthate label does describe is with oral anticoagulants, and its adverse reaction list includes bleeding in patients on concomitant anticoagulant therapy [2].

Does saw palmetto help BPH symptoms or hair loss?

For urinary symptoms from an enlarged prostate, the answer from the trials is largely no. A 2023 Cochrane review of 27 studies in 4,656 men found little or no benefit for BPH symptoms, with an adverse-event risk ratio of 1.01 [10]. In CAMUS, symptom scores fell 2.20 points on saw palmetto versus 2.99 on placebo, a 0.79-point difference favouring placebo [13]. In STEP, the difference in symptom score was 0.04 points (95% CI -0.93 to 1.01) [5]. NCCIH's conclusion is that saw palmetto is probably not helpful for BPH urinary symptoms [9].

For hair loss, NCCIH says the evidence is too limited to reach conclusions [9]. One open-label study of 100 men with male pattern hair loss followed men for 24 months: hair growth improved in 38% of those on saw palmetto 320 mg/day versus 68% of those on finasteride 1 mg/day [14].

Doses used in these studies were 160 mg twice daily for a year in STEP [5], 320 mg/day escalating to 960 mg/day over 72 weeks in CAMUS [13], 320 mg/day for 24 months in the hair-loss study [14], and 160 mg/day for 5 weeks before prostate surgery [8]. These are study doses, not recommended doses.

What does the testosterone enanthate label flag?

• Dosing and route: 50 to 400 mg every 2 to 4 weeks, injected slowly deep into the gluteal muscle, with total doses above 400 mg per month generally not required and injections more often than every 2 weeks rarely indicated [2].
• Blood pressure: the label says testosterone can increase blood pressure, which can increase cardiovascular risk over time, that blood pressure should be monitored periodically, and that these products are not recommended in uncontrolled hypertension [2]. FDA's 2025 class-wide action said ambulatory blood pressure studies confirmed a blood pressure increase with all testosterone products [15].
• Cardiovascular language: the enanthate label still carries the older text, which says long-term clinical safety trials have not been conducted, that epidemiologic studies and randomized trials have been inconclusive for major adverse cardiovascular events, and that some but not all studies reported an increased risk [2]. TRAVERSE, the trial behind FDA's newer labeling, tested daily 1.62% testosterone gel (not injections) against placebo gel in 5,246 men, with a primary cardiovascular event rate of 7.0% on testosterone versus 7.3% on placebo (hazard ratio 0.96, 95% CI 0.78 to 1.17) [16].
• Hematocrit: polycythemia is listed among hematologic adverse reactions [2]. A network meta-analysis of 29 placebo-controlled trials in 3,393 men found intramuscular testosterone enanthate/cypionate raised mean hematocrit by 4.0% (95% CI 2.9 to 5.1) versus placebo [17]. The Endocrine Society guideline recommends monitoring hematocrit, serum testosterone and prostate cancer risk during the first year of therapy [18].
• Clotting: venous thromboembolism, including deep vein thrombosis and pulmonary embolism, has been reported with testosterone products, and the label says to discontinue treatment if one is suspected [2].
• Breast tissue: the label says gynecomastia frequently develops and occasionally persists in men treated for hypogonadism [2].
• Contraindications: carcinoma of the breast, known or suspected carcinoma of the prostate, women who are or may become pregnant, and hypersensitivity to any component [2].

Is saw palmetto well tolerated?

NCCIH describes saw palmetto as well tolerated, used safely in research studies for up to 3 years, with mild and infrequent side effects that may include digestive symptoms, dizziness and headache [9].

The 225-man STEP safety analysis found serious adverse events in 5.4% on saw palmetto versus 9.7% on placebo (p=0.31) and non-serious symptoms in 34.8% versus 30.1% (p=0.48), with only small differences in bilirubin, potassium and glycosuria and no serious toxicity observed, though rare effects could not be ruled out [19].

Saw palmetto is sold as a dietary supplement rather than an approved drug; a Drugs@FDA search for saw palmetto or Serenoa returned no approved drug application [20][9].