Can I Take Saw Palmetto With Tretinoin?

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Has anyone tested saw palmetto with topical tretinoin?

We found no study that tested saw palmetto together with topical tretinoin, so any statement about combining them is inference rather than measurement. What can be described is each product's own documented effects. NCCIH lists saw palmetto's side effects as mild and infrequent: digestive symptoms, dizziness and headache [1]. The Renova label lists tretinoin's reactions as mainly local to the skin where it is applied [2].

The Renova label does name other medicines in two places. It says the cream should not be given to patients also taking drugs known to be photosensitizers, such as thiazides, tetracyclines, fluoroquinolones, phenothiazines and sulfonamides, because of the possibility of augmented phototoxicity. It also says concomitant topical medications and skin-irritating products should be used with caution because they may increase irritation [2].

What saw palmetto does, and does not do

Saw palmetto is the berry extract of Serenoa repens, sold over the counter as a dietary supplement. Dietary supplements are not approved by the FDA before they are sold [1]. It is promoted for urinary symptoms of an enlarged prostate, hair loss and prostatitis. A 2023 review of 27 studies found little or no benefit for BPH symptoms, and the evidence for hair loss is too limited to reach conclusions [1].

Saw palmetto does not act like finasteride on hormone levels. In a one-week randomized, placebo-controlled study of 32 healthy men aged 20 to 30, serum DHT did not change on the saw palmetto extract Permixon, the same as placebo, while finasteride 5 mg lowered DHT by 52% to 65% [3].

What the Renova 0.02% label says

Topical tretinoin is a prescription retinoid. The product label described here is Renova (tretinoin cream) 0.02%, indicated as an adjunct, alongside a comprehensive skin care and sunlight avoidance program, for mitigation of fine facial wrinkles. The same label states that Renova does not eliminate wrinkles, repair sun-damaged skin, reverse photoaging or restore more youthful skin [2].

The label's directions: wash the face gently with a mild soap, pat the skin dry, wait 20 to 30 minutes, then apply a small pearl-sized amount, about 1/4 inch or 5 mm across, once a day in the evening. Use only enough to cover the affected area lightly, and avoid the eyes, ears, nostrils and mouth [2].

On absorption, the label states that no percutaneous absorption study was conducted with Renova 0.02% in human volunteers. Its pharmacology section describes a separate 0.05% cream formulation, in which absorption was less than 2% of the applied dose in healthy men after a single application (n=7) and after 28 days of daily use (n=7). Across topical formulations, transdermal absorption ranged from 1% to 31% of the applied dose, depending on whether skin was healthy or inflamed [2].

Is bleeding a real concern with saw palmetto?

The concern traces to a single 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 [5].

A controlled study points the other way. In 75 men scheduled for prostate resection, saw palmetto 160 mg/day for 5 weeks (27 men) produced no significant difference in intraoperative blood loss compared with 21 controls or 27 men taking dutasteride 5 mg/day [6]. We found no study of saw palmetto with warfarin or other anticoagulants.

What you might notice from each

Saw palmetto: NCCIH describes it as well tolerated and used safely in research studies for up to 3 years, with mild and infrequent side effects that may include digestive symptoms, dizziness and headache. It says saw palmetto may be unsafe during pregnancy or while breastfeeding [1]. In the 225-man STEP safety analysis of 160 mg twice daily versus placebo over one year, serious adverse events occurred in 5.4% versus 9.7% (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 [9].

Tretinoin: in double-blind, vehicle-controlled studies involving 339 patients who applied Renova 0.02% to the face, almost all reported one or more local reactions such as peeling, dry skin, burning, stinging, erythema and pruritus. In 32% of all study patients, skin irritation was reported that was severe, led to temporary discontinuation, or led to use of a mild topical corticosteroid, and about 4% discontinued because of adverse reactions [2]. The label also warns of heightened sunburn susceptibility, advises sunscreens with a minimum SPF of 15 and protective clothing, and says patients with sunburn should not use the cream until fully recovered [2].

Pregnancy

The Renova label directs that the cream not be used if the patient is pregnant, attempting to become pregnant or at high risk of pregnancy. Its pregnancy section notes that oral tretinoin is teratogenic in animals and that topical tretinoin in animal teratogenicity tests has given equivocal results. It also notes that 30 human cases of temporally associated congenital malformations were reported over two decades of clinical use of another formulation of topical tretinoin, with no definite pattern of teratogenicity and no causal association established [2].

NCCIH says saw palmetto may be unsafe for use during pregnancy or while breastfeeding [1].

Skin and sun precautions on the Renova label

The Renova label's cautions concern the skin and the sun. It says to avoid or minimize exposure to sunlight, including sunlamps, to use sunscreen of at least SPF 15 and protective clothing, and to keep the cream out of the eyes, mouth, angles of the nose and mucous membranes [2]. It says products that irritate the skin should be used with caution because they may increase irritation. It lists medicated or abrasive soaps, cleansers and cosmetics with a strong drying effect, products with high concentrations of alcohol, astringents, spices or lime, permanent wave solutions, electrolysis, and hair depilatories and waxes [2].