Can I Take Saw Palmetto with MK-677 (Ibutamoren)?

What MK-677 (Ibutamoren) Actually Does in the Body

MK-677 is a non-peptide ghrelin receptor agonist that stimulates the pituitary to release growth hormone (GH) in a pulsatile pattern, which in turn raises insulin-like growth factor 1 (IGF-1). A 24-month randomized trial by Nass et al. (N=65 elderly adults) found that 25 mg/day ibutamoren raised mean IGF-1 by approximately 60% above baseline [1]. MK-677 is taken orally, which distinguishes it from injectable GH secretagogues.

How GH and IGF-1 Affect Androgens

Elevated GH and IGF-1 do not directly raise testosterone, but they can amplify 5-alpha-reductase (5-AR) activity in peripheral tissues. 5-AR converts testosterone to dihydrotestosterone (DHT), the androgen primarily responsible for prostate growth, scalp follicle miniaturization, and sebum production [2]. A study in the Journal of Clinical Endocrinology and Metabolism demonstrated that GH replacement in GH-deficient adults raised DHT-to-testosterone ratios, consistent with increased 5-AR flux [3]. MK-677's ability to mimic GH replacement means it may produce a similar androgenic shift.

MK-677 and Insulin Sensitivity

MK-677 reliably raises fasting glucose and fasting insulin. In the Nass et al. Trial, fasting blood glucose increased by approximately 0.3 mmol/L at 12 months [1]. The FDA has not approved MK-677 for any indication, and the agency classifies it as an unapproved new drug [4]. Practitioners monitoring users should include a fasting metabolic panel at baseline and every 3 months.

What Saw Palmetto Does and Why It Matters Here

Saw palmetto (Serenoa repens) is a standardized liposterolic extract used primarily for benign prostatic hyperplasia (BPH) symptom relief. Its main mechanism is competitive inhibition of both type 1 and type 2 5-alpha-reductase [5]. A Cochrane systematic review of 32 trials (N=5,666) found that 320 mg/day standardized saw palmetto extract produced modest but statistically significant improvements in urinary flow scores compared with placebo, though a large NIDDK-funded trial (STEP trial, N=225) showed no significant benefit over placebo at 1 year [6].

The 5-AR Inhibition Overlap

Because MK-677 may increase 5-AR activity and saw palmetto inhibits 5-AR, the two agents work in opposing directions on the same enzymatic step. The net effect on serum DHT will depend on the relative magnitude of each influence. Finasteride, a pharmaceutical 5-AR inhibitor, reduces serum DHT by roughly 70% at 5 mg/day [7]. Saw palmetto's DHT-lowering effect is considerably smaller. One 6-month randomized trial by Marks et al. Found that 320 mg/day saw palmetto reduced intraprostatic DHT by approximately 32% versus 85% for finasteride [8]. So saw palmetto is unlikely to fully counteract a strong MK-677-driven DHT rise, but it may attenuate it.

Saw Palmetto's Antiplatelet Activity

Saw palmetto inhibits cyclooxygenase and has been associated with perioperative bleeding in case reports. The American Society of Anesthesiologists recommends discontinuing herbal supplements including saw palmetto at least 2 weeks before elective surgery because of antiplatelet and potential hormonal effects [9]. MK-677 causes sodium and water retention, which raises blood pressure in some users. Combining a mild antiplatelet agent with a compound that raises blood pressure could modestly raise bleeding risk, though no clinical trial has quantified this combination specifically.

Is This a Pharmacokinetic or Pharmacodynamic Interaction?

The interaction is pharmacodynamic, not pharmacokinetic. MK-677 is metabolized primarily by CYP3A4 based on in vitro data from Merck's original development program [10]. Saw palmetto has not been shown to meaningfully inhibit or induce CYP3A4 at standard supplemental doses in clinical pharmacokinetic studies [11]. A formal pharmacokinetic interaction study pairing the two agents does not exist in the published literature as of this article's review date.

What "Pharmacodynamic Interaction" Means Clinically

A pharmacodynamic interaction means plasma concentrations of each agent are not changed by the other, but their biological effects overlap at the tissue level. In this case, both agents act on the androgen axis (one upstream by raising GH/IGF-1, one downstream by blocking DHT synthesis), and their cardiac and fluid effects may add together. Clinicians should monitor for signs of fluid overload, elevated blood pressure, and unexpected changes in androgenic markers when both are used simultaneously.

Does Saw Palmetto Blunt MK-677's Intended Effects?

This depends on why someone is using MK-677. Research users seeking muscle accretion, improved body composition, or GH pulse restoration are unlikely to find saw palmetto significantly new to those goals, since 5-AR inhibition does not reduce GH or IGF-1 levels. A 12-month study by Murphy et al. (N=24 older men) confirmed that ibutamoren significantly increased lean body mass and reduced fat mass without a DHT-mediated mechanism being central to those outcomes [12].

When Saw Palmetto Might Be Deliberately Beneficial

Some MK-677 users report scalp shedding or increased sebum production consistent with a DHT rise. Saw palmetto at 320 mg/day has been studied as a hair-loss intervention. A 2012 randomized trial by Prager et al. (N=100) found that 38% of saw palmetto-treated men showed hair density improvement versus 24% placebo [13]. For MK-677 users experiencing androgenic side effects, adding saw palmetto may offer a partial protective effect on hair follicles without meaningfully interfering with GH-axis goals.

When Saw Palmetto Could Be Counterproductive

If the clinical goal is prostate health monitoring, adding saw palmetto while on MK-677 complicates PSA interpretation. Both GH/IGF-1 elevation and 5-AR inhibition affect PSA: GH may raise PSA through prostate growth stimulation, while saw palmetto reduces PSA by roughly 10 to 15% in some studies [14]. The net effect is unpredictable, making PSA an unreliable screening marker in this combination.

The HealthRX Decision Framework: Should You Combine These Two?

The following framework reflects the clinical reasoning the HealthRX medical team applies when a patient presents using both agents. It is not a substitute for individualized medical advice.

Step 1. Clarify the goal for each agent. MK-677 goal: GH pulse restoration, body composition, or sleep quality. Saw palmetto goal: BPH symptom relief, hair retention, or prostate protection during GH-axis stimulation.

Step 2. Assess baseline androgenic status. Order serum total testosterone, free testosterone, and DHT before starting both agents. Repeat at 8 weeks. A DHT elevation above 10% from baseline on MK-677 alone supports a rational case for adding saw palmetto.

Step 3. Check bleeding risk. Review concurrent anticoagulants (warfarin, apixaban, aspirin) and NSAIDs. Saw palmetto's antiplatelet activity becomes clinically relevant with any additional anticoagulant burden [9].

Step 4. Suspend PSA as a sole prostate screening tool. If PSA monitoring is clinically indicated (men over 50, family history), use multiparametric MRI or a PCA3 urine test as adjuncts. Document in the chart that saw palmetto use may suppress PSA by up to 15% [14].

Step 5. Reassess at 12 weeks. Measure IGF-1, fasting glucose, blood pressure, DHT, and any subjective androgenic side effects. Adjust saw palmetto dose or discontinue if the target effect (DHT attenuation) is not justified by symptom burden.

Dosing Considerations If You Decide to Use Both

Standard research doses of MK-677 range from 10 mg to 25 mg taken orally once daily, typically at night to align with the natural GH pulse [1]. Saw palmetto is used at 320 mg/day of a standardized liposterolic extract (standardized to 85 to 95% fatty acids and sterols) in virtually all published trials [6].

Timing and Separation

No pharmacokinetic data support a mandatory dose-separation window for these two agents, since the interaction is pharmacodynamic. Taking saw palmetto with a meal (as recommended to reduce GI upset) and MK-677 at bedtime achieves de facto separation without a specific clinical rationale being required [5].

Duration of Use

MK-677 trials have run as long as 24 months continuously [1]. Saw palmetto trial durations in BPH literature range from 6 weeks to 24 months [6]. No safety data exist for combinations beyond 6 months in research settings.

Safety Profile of Each Agent Individually

MK-677 Safety Data

Common adverse effects from clinical trials include edema (reported in up to 28% of participants), increased appetite, mild hyperglycemia, and transient muscle aches [1]. The agent is not FDA-approved, and long-term cardiovascular safety has not been established in large trials. The FDA has issued warning letters to companies marketing MK-677 as a dietary supplement, clarifying it does not meet the statutory definition of a supplement [4].

Saw Palmetto Safety Data

Saw palmetto is generally well tolerated. A 2012 Cochrane review found adverse event rates similar to placebo [6]. Rare case reports link saw palmetto to hepatotoxicity and pancreatitis, though causality remains uncertain [15]. The Natural Medicines database rates saw palmetto as "possibly safe" for up to 3 years of oral use at standard doses.

Populations Who Should Avoid This Combination

Certain groups face disproportionate risk from either agent or the combination.

Individuals on anticoagulation therapy should avoid saw palmetto due to additive bleeding risk [9]. People with type 2 diabetes or impaired fasting glucose should avoid MK-677 without close glucose monitoring, as ibutamoren raises fasting glucose and insulin [1]. Women who are pregnant or breastfeeding should avoid both agents. Neither has established safety data in pregnancy, and MK-677 has not been studied in women at reproductive doses. Adolescents with open growth plates should not use MK-677, as supraphysiologic GH signaling during active growth carries unpredictable skeletal risk.

What Clinicians and Guidelines Say

The Endocrine Society's 2019 clinical practice guideline on growth hormone therapy states: "GH and IGF-1 excess increases 5-alpha-reductase activity in peripheral tissues, which may raise DHT concentrations and exacerbate androgen-sensitive conditions" [16]. This is the mechanistic basis for anticipating that MK-677, by raising GH and IGF-1, could increase androgenic activity in susceptible users.

The American Urological Association 2021 BPH guideline notes that 5-alpha-reductase inhibitors (including herbal agents with 5-AR activity) reduce prostate volume and PSA, and recommends that clinicians document all 5-AR-active agents before interpreting PSA results [17].

No published guideline specifically addresses MK-677 combined with saw palmetto, reflecting the compound's non-approved status and the general absence of combination supplement-drug interaction guidelines for research compounds.

Monitoring Checklist for Concurrent Use

The following labs and assessments cover the major risk domains for someone already using or considering both agents.

At baseline (before starting): Fasting glucose, HbA1c, IGF-1, serum total testosterone, free testosterone, DHT, PSA (men over 40), complete blood count, blood pressure, weight.

At 8 weeks: IGF-1, fasting glucose, DHT, blood pressure, weight, subjective hair and skin changes.

At 12 weeks and every 3 months thereafter: Full repeat of baseline panel. PSA should be flagged in the chart as potentially suppressed by saw palmetto (estimated 10 to 15% reduction) [14].

Discontinue and seek evaluation if: Fasting glucose exceeds 126 mg/dL, systolic blood pressure rises above 140 mmHg, unexpected bruising or prolonged bleeding occurs, or signs of hepatotoxicity appear (jaundice, right upper quadrant pain, elevated ALT/AST) [15].