Batana natural hair growth oil: what it actually does for edges

Last updated 2026-07-09

What is batana oil and where does it come from?

Batana oil comes from the nut of the American oil palm, Elaeis oleifera, native to Central America and parts of northern South America. The Miskito people of Honduras and Nicaragua have pressed and used it for generations, calling it "ojon" in some regional dialects. They apply it to hair and skin as a conditioning treatment, and the oil's reputation for producing thick, shiny hair is how it entered the global beauty conversation.

The extraction process matters. Traditionally, the nuts are sun-dried, roasted, boiled, and then hand-pressed, yielding a dark reddish-brown oil with a smoky, earthy scent. Cold-press or expeller-press methods used commercially preserve more of the tocotrienols (a form of vitamin E) and unsaturated fatty acids. Heat-extracted or solvent-extracted versions are cheaper but chemically poorer. If a bottle of batana oil is pale or odorless, that's a sign of heavy refinement or adulteration.

The oil is sometimes confused with red palm oil, which comes from the African species Elaeis guineensis. They share a similar color and some overlapping fatty acids, but they're different plants, different fatty acid ratios, and different traditional uses. Batana from E. oleifera has a higher proportion of oleic acid (omega-9) and somewhat lower saturated fat than African palm oil, which is part of why cosmetic formulators have taken interest in it ^[1].

Supply is limited. Most commercial batana oil is sourced from Honduras, and because harvesting is still largely small-scale and manual, prices run higher than commodity oils. A 2-oz bottle from a reputable source typically costs $20 to $45 as of mid-2025. Anything priced well below that range is worth scrutinizing.

What does batana oil actually contain that could help hair?

The functional case for batana oil rests on its composition, not on hair-specific clinical trials. Here's what the research on the oil's chemistry shows ^[1][2]:

Oleic acid (omega-9) makes up roughly 50 to 70% of batana oil's fatty acid profile, depending on the source and processing method. Oleic acid is a small enough molecule to partially penetrate the hair shaft, which is why oils high in oleic acid (think olive oil and avocado oil) reduce hygral fatigue, the swelling and contraction cycle that causes breakage in textured hair. For edges that are already weakened, reducing mechanical breakage from humidity cycling matters.

Palmitic acid accounts for another 15 to 25% of the oil. It's a saturated fatty acid that coats the hair surface, smoothing the cuticle and reducing surface friction. Less friction means less tangling and less mechanical stress during detangling, both relevant for fine, fragile hairline hairs.

Tocotrienols are the part of the story that most batana oil marketing latches onto. A 2010 study published in Tropical Life Sciences Research found that oral tocotrienol supplementation (at 100 mg/day) increased hair count by 34.5% in people with alopecia compared to a 0.1% increase in the placebo group ^[3]. That's a real finding. But it was an oral supplement study, not a topical oil study, and the dose was standardized. Whether rubbing batana oil on your scalp delivers a pharmacologically meaningful amount of tocotrienol to hair follicles is unknown. Nobody has done that study.

Carotenoids give batana its red-orange color and act as antioxidants. Oxidative stress at the follicle level is associated with some forms of hair thinning ^[4], and antioxidants in the local scalp environment are plausibly beneficial, but again, no topical batana trial exists to confirm this.

The honest summary: batana oil has a genuinely good fatty acid and antioxidant profile for scalp and hair conditioning. Calling it a proven hair growth oil overstates the evidence. Calling it a good conditioning oil with plausible supportive properties for a compromised hairline is accurate.

How does batana oil compare to rosemary oil and other natural hair growth oils?

This is where things get useful, because the evidence is not equal across natural oils.

rosemary oil for hair growth has the strongest evidence of any natural oil for hair growth specifically. A 2015 randomized controlled trial published in SKINmed compared 2% minoxidil to rosemary oil in men with androgenetic alopecia over six months. Both groups showed similar increases in hair count by the endpoint ^[5]. That's a real comparison study with a real control. Rosemary oil works at least partly by inhibiting 5-alpha reductase and improving scalp circulation. It's the oil I'd choose first if stimulating follicle activity is the primary goal.

Batana oil plays a different role. It's better thought of as a conditioning and protective oil than a growth stimulant. The oleic acid content helps with penetration and moisture retention, and the tocotrienols support follicle health indirectly. For someone with traction alopecia or damage-related thinning, where the problem is mechanical stress and inflammation rather than DHT sensitivity, a rich conditioning oil like batana may actually be more directly useful than rosemary oil. You'd ideally use both, at different points in a routine.

The table below shows how the main natural oils compare on the factors that matter for thinning edges:

Oil	Best evidence for	Follicle penetration potential	Main limitation
Rosemary (Salvia rosmarinus)	Androgenetic alopecia	Low (works on scalp surface/circulation)	Needs dilution; can irritate
Batana (Elaeis oleifera)	Conditioning, breakage reduction	Moderate (oleic acid)	No hair growth RCTs
Castor oil	Anecdotal edge growth	Very low (thick, sits on surface)	No clinical evidence; occlusive
Peppermint oil	Follicle activation (1 mouse study)	Low (essential oil, needs carrier)	Very limited human data
Jamaican Black Castor	Anecdotal	Very low	No clinical evidence
Coconut oil	Reducing protein loss	High (lauric acid structure)	Can worsen low-porosity hair

Nobody has good comparative data on batana versus other conditioning oils specifically for edges. The closest we can get is extrapolating from fatty acid penetration studies ^[2], which is imperfect but it's what's available.

If you want a broader look at the essential oils for natural hair growth research landscape, the evidence thins out quickly once you move past rosemary.

Tocotrienol group (100 mg/day)	34.5%
Placebo group	0.1%

Source: Tropical Life Sciences Research, Beoy et al. 2010

Can batana oil help with traction alopecia and thinning edges specifically?

Traction alopecia is mechanical damage to hair follicles from chronic tension, and it's the most common cause of hairline thinning in Black women. The American Academy of Dermatology notes that traction alopecia accounts for a significant portion of hair loss cases in women of African descent, and that early-stage hair loss from traction is often reversible if the tension is removed ^[6]. Later-stage traction alopecia involves fibrosis of the follicle, and at that point no oil, prescription or otherwise, can grow hair from scarred tissue.

For everything short of scarring, batana oil's role is supportive, not curative. Here's what it can realistically do:

Reduced breakage from daily manipulation. Edge hairs are fine and fragile. Coating them with a rich fatty acid blend before styling reduces friction and makes them less likely to snap when you pull them back or apply edge product. Less breakage means the hair you have grows longer visibly, even without any change in follicle activity.

Scalp moisturization. A dry, tight scalp increases the physical tension from styles that pull. Keeping the scalp supple doesn't eliminate traction but may reduce the constant low-level stress at the follicle. Nobody has quantified how much this matters.

Anti-inflammatory antioxidants. Some forms of hair loss involve low-grade scalp inflammation ^[4], and batana's carotenoids and tocotrienols may help modulate that environment. This is plausible mechanistically, not proven topically.

What batana oil cannot do: reverse scarred follicles, counteract ongoing traction from tight styles, or replace the clinical interventions (like corticosteroid injections or PRP, depending on severity) that a dermatologist might recommend for significant traction alopecia. If your edges are actively receding in a band pattern at the hairline, see a board-certified dermatologist before spending money on oils ^[6].

More background on traction alopecia and the stages that are and aren't responsive to conservative treatment is worth reading if you're trying to figure out where you actually are in the process.

How do you use batana oil on your edges correctly?

Application technique matters more than most product marketing admits. Getting the oil to the scalp rather than just on the hair shaft is the difference between conditioning your follicle environment and just coating your hair.

Start with a clean, slightly damp scalp. Batana oil is heavy enough that applying it to dry skin can feel greasy without good penetration. Damp skin and scalp have more open cuticle structure and slightly expanded skin surface that receives oils better. But dripping wet is too much water, and it will dilute and push the oil off before it absorbs.

Use less than you think you need. For edges, one or two drops per side is enough. Warm the oil between your fingertips and press it into the scalp at the hairline, then work outward with light circular massage for 30 to 60 seconds per side. Scalp massage itself has some evidence behind it: a small Japanese study (n=9) showed that daily 4-minute scalp massage for 24 weeks increased hair thickness ^[7]. Pairing massage with oil application costs nothing extra.

For deeper conditioning, apply a thin layer to the edges before protective styling and cover overnight with a satin-lined bonnet or scarf. This is sometimes called a "hot oil treatment" but the heat isn't strictly necessary. The prolonged contact time matters more.

Batana's scent is distinctive and strong. It has a smoky, almost nutty odor that comes from the traditional roasting process. If you're sensitive to scent or plan to wear your hair in a professional setting, apply it at night and wash or rinse the hairline lightly in the morning. Some people mix it with a lighter, more neutral oil (like squalane or fractionated coconut oil) at a 1:3 ratio to thin the texture and dilute the scent.

Frequency: two to three times per week for regular maintenance. Daily use isn't harmful, but it increases buildup on fine hairline hairs, which can weigh them down and increase breakage paradoxically if you're not cleansing regularly.

Avoid edge control products with high alcohol content immediately after applying batana. Alcohol will strip the oil before it has time to condition. If you need hold, apply the oil the night before and the edge styler in the morning.

What do batana oil reviews actually say, and how reliable is that feedback?

Batana natural hair growth oil reviews across retail platforms show a consistent pattern. Users with dry, high-porosity, or chemically processed hair report the most visible improvement, describing reduced breakage, more shine, and edges that feel softer within two to four weeks. Users with low-porosity natural hair sometimes report buildup and heaviness without obvious benefit.

This tracks with what we know about oleic acid oils generally. High-porosity hair absorbs oleic-rich oils more readily because the cuticle is more open. Low-porosity hair needs heat or pre-cleansing to improve absorption ^[2].

Veganic natural hair growth oil reviews are a separate category worth noting. Some brands market their edge oils as "veganic" (vegan plus organic certified), and a subset of those formulas include batana as a hero ingredient alongside rosemary, peppermint, or black seed oil. Reviews for these blended products are harder to attribute to any single ingredient, which is a real problem for figuring out what's doing the work. If you're trying to assess batana specifically, a single-ingredient product gives you cleaner feedback from your own hair.

The most commonly cited negatives in batana natural hair growth oil reviews:

The smell. It divides people. Some find it pleasant and earthy; others find it off-putting. There's no neutral position here because the scent is strong and lingers.

Color transfer. Batana is red-orange. On light-colored pillowcases or clothing, it stains. Satin bonnets that you don't mind staining are the practical solution.

Price and purity uncertainty. Because batana is a trending ingredient, adulteration is common. Several independent beauty testers have noted that many products labeled "batana oil" contain predominantly other oils with a small percentage of batana for marketing purposes. There's no standardized test a consumer can easily run, but comparing color (should be distinctly reddish-orange to dark red), scent (smoky, earthy), and texture (heavier than argan, lighter than castor) helps screen out obviously diluted products.

The honest read on batana reviews: it performs well as a conditioning oil for fragile edges and delivers consistent benefits for breakage reduction. Claims of dramatic regrowth in the reviews are harder to verify and confounded by everything else people change in their routines at the same time.

Is batana oil safe, and can it cause any side effects?

Batana oil has a long history of traditional topical use with no documented serious adverse effects in the published literature. That said, "no documented adverse effects" partly reflects limited formal study, more than confirmed safety.

Allergenicity: Elaeis oleifera is a palm species, and tree nut allergies occasionally cross-react with palm products, though palm is not among the top common allergens. If you have a known tree nut allergy, do a patch test on the inner wrist for 24 hours before applying to the scalp ^[8].

Acne and clogged follicles: Batana's comedogenic rating isn't formally established in the dermatological literature, but its oleic acid-dominant profile is similar to olive oil, which rates moderate (around 2/5) on the informal comedogenic scale used by cosmetic chemists. For most people applying it to the scalp hairline, follicular occlusion is not a significant concern at moderate use. For people with seborrheic dermatitis or scalp acne, heavy occlusive oils in general can worsen symptoms, so less is more.

Pregnancy and scalp conditions: No contraindications have been established for topical batana oil use. As with any topical product during pregnancy, a quick conversation with your OB is reasonable if you have concerns.

Environmental and ethical note: Most commercial batana comes from Miskito communities in Honduras. When sourcing, look for brands that state fair-trade purchasing or direct community partnerships. This isn't a safety issue, but it matters for long-term supply integrity and for supporting the communities whose traditional knowledge underlies the oil's use.

How long does it take to see results from using batana oil on edges?

This question deserves an honest answer because most oil marketing implies faster results than the biology supports.

Hair growth is slow. The average scalp hair grows about 6 inches (15 cm) per year, or roughly half an inch per month ^[9]. Edge hairs grow at roughly the same rate, though they can appear to grow more slowly because they're finer and more prone to breakage before they reach visible length.

For breakage reduction, which batana is well-suited for, you can see a real difference in four to eight weeks. Hair that was snapping at half an inch may now be reaching an inch before breaking, and that shows up as fuller, longer-looking edges without any change in follicle activity.

For regrowth from dormant but living follicles, such as early traction alopecia where the follicle isn't scarred, you're looking at a minimum of three to six months of consistent, gentle treatment before visible improvement. And that improvement depends far more on eliminating the source of traction than on any product you apply.

For postpartum hair shedding, which affects hairline hairs significantly in many Black women, the timeline is different. Postpartum shedding peaks around three to four months after delivery and typically resolves on its own by six to twelve months ^[10]. Batana oil during this period can help protect fragile regrowth hairs from breaking, but it's not treating the underlying hormonal cause. If you're dealing with postpartum hair loss, managing expectations and reducing mechanical stress on new growth matters more than any specific oil.

Here's the timing to expect: conditioning benefits in four to eight weeks, visible length retention in two to three months, and any meaningful structural regrowth only after sustained protective care over six or more months.

What should you look for when buying batana oil?

The batana oil market is crowded and adulteration is common. Here's what actually differentiates a quality product.

Color: genuine cold-pressed batana oil ranges from deep amber-orange to dark reddish-brown. It's distinctly pigmented. A pale gold or clear oil sold as batana has been heavily refined or blended down to the point where the beneficial compounds are largely gone.

Scent: traditional batana has a smoky, nutty, earthy smell from the roasting process. It's noticeable and distinctive. If a product smells neutral or generic, it's been deodorized, which involves heat processing that degrades tocotrienols.

Ingredient listing: INCI (International Nomenclature of Cosmetic Ingredients) listings for real batana oil use "Elaeis oleifera kernel oil" or "Elaeis oleifera fruit oil". If you see only "palm oil" or an unlisted proprietary blend, you can't confirm what you're getting.

Source transparency: the best batana oil producers disclose their sourcing region (Honduras or Nicaragua) and ideally their community sourcing model. This isn't just ethics, it's a quality signal, because oils with traceable supply chains are less likely to be adulterated.

Edge Naturale's product collection at edgenaturale.com includes edge growth oils you can review against these criteria if you're comparing options across formulations.

Price reality: $20 to $45 for a 2-oz bottle of authentic cold-pressed batana is reasonable. Under $10 for a "batana blend" is almost certainly a red flag. Over $60 for a small bottle of plain batana oil is probably marketing premium rather than quality premium.

For people exploring a broader range of options for natural hair growth products, batana works well as part of a multi-oil routine rather than a single solution.

Can batana oil be part of a routine for hair breakage and edge care?

Yes, and this is probably its strongest practical application. A good edge care routine addresses three things: scalp health, hair shaft integrity, and style protection. Batana contributes meaningfully to the first two.

A practical weekly structure might look like this:

Two to three nights per week: Apply one to two drops of batana oil to the hairline, massage for 60 seconds, and sleep with a satin bonnet. This is the core conditioning step.

Wash day (weekly or biweekly): Clarify lightly with a sulfate-free or mild sulfate cleanser to prevent buildup. Heavy oils accumulate and can actually increase breakage from product weight if not cleared regularly.

Styling days: Apply a lightweight oil or serum to damp edges before any hold product. If you need edge control, choose one without drying alcohols. Reserve the batana for conditioning nights rather than using it as a daily styler, because the texture and pigment aren't ideal under styling products.

For protective styling, batana applied before installation helps create a moisture reservoir under braids or twists. After protective style removal, hair breakage is often worst at the hairline because those hairs are under the most tension. A batana oil treatment during the first week after removing a style speeds up recovery.

Batana pairs well with rosemary oil in the same routine: rosemary addresses follicle stimulation and circulation, batana addresses conditioning and shaft protection. Mix them only if you're using rosemary already diluted in a carrier oil, because pure rosemary essential oil needs to stay at 0.5 to 1% concentration.

For context on protective hairstyles that don't stress the hairline further while you're nursing edges back, that's a separate conversation worth having in parallel with any topical treatment.

What the science says and what it doesn't: an honest summary

The scientific literature on batana oil for hair specifically is thin. There are no randomized controlled trials studying batana oil as a topical treatment for any form of hair loss, as of mid-2025. The evidence base for it is: traditional use, fatty acid composition data, and extrapolation from studies on its individual components.

The tocotrienol oral supplementation study from 2010 is real and significant ^[3]. The study's conclusion states: "Tocotrienol supplementation significantly increased the number of hairs in the volunteers." But translating that to topical application involves a chain of assumptions about penetration, bioavailability, and dose that hasn't been tested.

The broader picture of oils for hair is similarly underpowered. A 2021 review in the Journal of Cosmetic Dermatology concluded that while several plant oils show promising in vitro and anecdotal properties for hair and scalp health, "clinical evidence from well-designed human trials remains limited for most natural oils" ^[2]. That's an honest state of the field.

What this means practically: batana oil is a reasonable ingredient in an edge care routine. It's not a proven hair regrowth treatment. If you have significant hair loss, active traction alopecia, or a receding hairline that's been progressing for more than six months, topical oils alone aren't a substitute for a dermatology evaluation. The National Institutes of Health's resource on hair loss notes that treatment outcomes are substantially better when hair loss is addressed early, before follicle miniaturization or scarring progresses ^[4].

For fine-tuning your understanding of edges hair care beyond just oils, the context of the full hairline maintenance picture matters.

Frequently asked questions

Does batana oil actually regrow hair?

There are no clinical trials testing batana oil as a hair regrowth treatment. Its fatty acid and tocotrienol content support scalp conditioning and may help maintain a healthy follicle environment, but that's not the same as proven regrowth. A 2010 tocotrienol study showed results with oral supplementation, not topical oil. Expect breakage reduction and better hair retention, not guaranteed new follicle activation.

How long should you leave batana oil on your hair?

Overnight is ideal for edge conditioning. Apply one to two drops to the hairline, massage gently, and sleep with a satin bonnet. If you can't do overnight, 30 to 60 minutes as a pre-wash treatment delivers most of the benefit. Daily leave-in use is possible but increases buildup on fine hairline hairs, so pair it with regular clarifying on wash day.

Is batana oil or rosemary oil better for hair growth?

Rosemary oil has stronger evidence specifically for hair growth. A 2015 randomized trial found it performed comparably to 2% minoxidil for androgenetic alopecia over six months. Batana is a better conditioning oil, reducing breakage and supporting scalp moisture. For thinning edges from damage or traction, using both at different points in your routine makes more sense than choosing one.

Can batana oil help with traction alopecia?

Batana oil can support the scalp environment and reduce mechanical breakage, which is useful in early traction alopecia. But traction alopecia caused by ongoing tension from tight styles requires removing that tension first. No oil reverses late-stage traction alopecia where follicles have scarred. See a dermatologist if your hairline has been receding progressively, per AAD guidance on traction alopecia.

What does batana oil smell like?

Authentic cold-pressed batana oil smells smoky, earthy, and faintly nutty. The scent comes from the traditional roasting of the palm nuts before pressing. It's distinctive and noticeable, and lingers in hair for several hours. If a product labeled batana oil smells neutral or generic, it's likely been deodorized through heat processing, which also degrades its tocotrienols and antioxidants.

Is veganic natural hair growth oil with batana worth trying?

Blended oils marketed as veganic (vegan plus organic) sometimes include batana alongside rosemary, peppermint, or black seed oil. The benefit is a multi-ingredient approach; the drawback is it's harder to know which ingredient is doing the work. If you want clean, simple conditioning for edges, single-ingredient batana from a transparent source is easier to evaluate. Blends can be good, but read the full ingredient list.

Can I use batana oil every day on my edges?

You can, but two to three times per week tends to work better for most hair types. Daily use without regular cleansing leads to product buildup on fine hairline hairs, which can weigh them down and increase breakage. If you use it daily, cleanse the hairline lightly more than once a week. Low-porosity hair types especially benefit from less frequent application.

Does batana oil stain hair or skin?

Batana's reddish-orange carotenoids can stain light-colored pillowcases and fabrics. On dark hair and brown or deep skin tones, it doesn't cause visible color change with normal use. On very light or color-treated blonde hair, repeated heavy application could theoretically impart a slight warm cast, though this isn't a widely reported issue. Using a satin bonnet overnight is the practical workaround for fabric staining.

How do I know if batana oil is pure and not adulterated?

Look for deep reddish-orange color, a smoky earthy scent, and the INCI name "Elaeis oleifera kernel oil" or "Elaeis oleifera fruit oil" on the label. Transparent sourcing from Honduras or Nicaragua is a good sign. Pale, odorless, or very cheap products are likely diluted or heavily refined. Expect to pay $20 to $45 for 2 oz of authentic cold-pressed batana.

What natural oils stimulate hair growth with real evidence?

Rosemary oil has the strongest human trial evidence, matching 2% minoxidil in one 2015 randomized controlled trial for androgenetic alopecia. Peppermint oil has one promising animal study but limited human data. Tocotrienols (found in batana) showed results in a 2010 oral supplementation trial. Most other oils, including castor and Jamaican black castor, are supported mainly by anecdote.

Can batana oil be used during postpartum hair loss?

Batana oil can protect fragile regrowth hairs from breakage during the postpartum shedding period, which typically peaks three to four months after delivery. It doesn't address the hormonal cause of postpartum shedding, which resolves on its own by six to twelve months for most people. Reducing mechanical stress on the hairline, with gentle styles and conditioning oils, is the most useful approach during this period.

Is batana oil safe for sensitive scalps or people with scalp conditions?

Batana oil has no documented serious adverse effects in the literature. People with tree nut allergies should patch test first, as Elaeis oleifera is a palm species. For seborrheic dermatitis or scalp acne, heavy occlusive oils can worsen symptoms. If you have an active scalp condition, check with a dermatologist before adding any new oil, including batana, to your routine.

How is batana oil different from Jamaican black castor oil for edges?

Both are popular for edges but they work differently. Batana is oleic acid-dominant with high tocotrienol content, giving it good partial penetration and antioxidant properties. Jamaican black castor oil is ricinoleic acid-dominant and very thick, coating the surface but penetrating poorly. There's no clinical trial evidence for either specifically for edges, but batana's chemistry is better suited to conditioning fragile hair strands.

Sources

1. USDA Agricultural Research Service, phytochemical database on Elaeis oleifera: Batana oil from Elaeis oleifera has a higher proportion of oleic acid and lower saturated fat compared to African palm oil (Elaeis guineensis)
2. Journal of Cosmetic Dermatology, 2021 review: 'Plant oils and their application in cosmetics and hair care': Clinical evidence from well-designed human trials remains limited for most natural oils used in hair and scalp care; oleic acid-rich oils penetrate the hair shaft and reduce hygral fatigue
3. Tropical Life Sciences Research, 2010: 'Tocotrienol Supplementation Improved Alopecia' (Beoy et al.): Oral tocotrienol supplementation at 100 mg/day increased hair count by 34.5% vs 0.1% in placebo group in subjects with alopecia
4. National Institutes of Health, MedlinePlus: Hair Loss: Treatment outcomes for hair loss are substantially better when addressed early before follicle miniaturization or scarring progresses; oxidative stress is associated with some forms of hair thinning
5. SKINmed Journal, 2015: 'Rosemary oil vs. minoxidil 2% for the treatment of androgenetic alopecia' (Panahi et al.): Rosemary oil performed comparably to 2% minoxidil at six months in a randomized controlled trial for androgenetic alopecia
6. ePlasty, 2016: 'Standardized Scalp Massage Results in Increased Hair Thickness' (Koyama et al.): Daily 4-minute scalp massage for 24 weeks significantly increased hair thickness in a 9-participant study
7. American Academy of Allergy, Asthma and Immunology, tree nut allergy guidance: Tree nut allergies may occasionally cross-react with palm-derived products; patch testing is recommended for those with known tree nut allergies
8. American Academy of Dermatology, Hair Loss: Overview: Average scalp hair grows approximately 6 inches (15 cm) per year, or about half an inch per month
9. American College of Obstetricians and Gynecologists, postpartum hair loss FAQ: Postpartum hair shedding peaks around three to four months after delivery and typically resolves on its own by six to twelve months
10. NIH National Center for Complementary and Integrative Health, natural products for hair: Most topical natural oil treatments for hair loss lack large-scale randomized controlled trial evidence; traditional use does not establish clinical efficacy