Symptoms of Low Borage Oil: Causes and Treatment
Deficiency
Symptoms & causes
Borage oil is not a nutrient — it is a plant seed oil with the highest GLA (gamma-linolenic acid) content of any common oil, but no deficiency syndrome exists; its primary evidence base is in atopic eczema and rheumatoid arthritis, and it carries a pyrrolizidine alkaloid contamination safety concern that is consistently omitted from wellness content.
Borage oil, pressed from the seeds of the Borago officinalis plant, is the richest plant source of gamma-linolenic acid (GLA), an omega-6 fatty acid. Despite its popularity in wellness circles, there is no recognized deficiency syndrome for borage oil or GLA. The most honest framing for its use is not correcting a deficiency, but potentially bypassing impaired enzymatic conversion of linoleic acid to GLA in certain health conditions. Critically, borage oil carries a unique safety risk—pyrrolizidine alkaloid contamination—that is almost entirely absent from consumer-facing content, making product quality and certification essential.
This is general nutrition and wellness information, not medical advice. If you're on a weight-loss medication or managing a health condition, confirm specifics with your clinician.
Symptoms of low Borage oil (Borago officinalis seed oil) — cold-pressed from borage seeds; the richest common plant source of gamma-linolenic acid (GLA), an omega-6 fatty acid. GLA content: approximately 20–26% of total fatty acids. Compare to evening primrose oil (~8–10% GLA) and black currant seed oil (~15–20% GLA). Other fatty acids: linoleic acid (~35%), oleic acid (~17%), palmitic acid (~10%). GLA is synthesized endogenously from linoleic acid (LA) via the delta-6-desaturase enzyme — making borage oil non-essential (GLA is a metabolite, not an essential fatty acid). Key safety concern: borage plants contain pyrrolizidine alkaloids (PAs) — hepatotoxic and potentially carcinogenic compounds; borage oil should be PA-free (UPA — unsaturated pyrrolizidine alkaloid-free) but quality control varies significantly across products.
Everyday signs are on the left; the ones on the right mean it's time to check in with a clinician.
Everyday signs
Common symptoms
- No symptoms attributable to low borage oil intake
- Dry, itchy skin and eczema flares are caused by atopic disease, not borage oil insufficiency
- Joint inflammation is caused by inflammatory conditions, not borage oil insufficiency
- Symptoms driving searches reflect real conditions but are not evidence of a deficiency
Don't wait
See a doctor if
- Persistent eczema warranting dermatological evaluation
- Joint inflammation warranting rheumatological evaluation
- Liver symptoms (jaundice, right upper quadrant pain, fatigue with dark urine) — especially if using a non-PA-free borage oil product
- Any concern about drug interactions with anticoagulants, antiplatelets, or psychiatric medications
Who is most likely to run low
Some people are more prone to falling short than others — including many people on a weight-loss journey who are simply eating less.
- No deficiency population exists
- People with impaired delta-6-desaturase activity (elderly, type 2 diabetics, high-trans-fat diet) may have reduced endogenous GLA synthesis — the practical target population for GLA supplementation from borage oil
What causes low Borage oil (Borago officinalis seed oil) — cold-pressed from borage seeds; the richest common plant source of gamma-linolenic acid (GLA), an omega-6 fatty acid. GLA content: approximately 20–26% of total fatty acids. Compare to evening primrose oil (~8–10% GLA) and black currant seed oil (~15–20% GLA). Other fatty acids: linoleic acid (~35%), oleic acid (~17%), palmitic acid (~10%). GLA is synthesized endogenously from linoleic acid (LA) via the delta-6-desaturase enzyme — making borage oil non-essential (GLA is a metabolite, not an essential fatty acid). Key safety concern: borage plants contain pyrrolizidine alkaloids (PAs) — hepatotoxic and potentially carcinogenic compounds; borage oil should be PA-free (UPA — unsaturated pyrrolizidine alkaloid-free) but quality control varies significantly across products.
- Not applicable — no deficiency exists for borage oil or GLA
- Reduced delta-6-desaturase enzyme activity (aging, diabetes, high trans-fat diet) reduces endogenous GLA synthesis — the closest analog to a 'low GLA' physiological state, but not a recognized deficiency syndrome
How low levels are diagnosed
No diagnostic test for borage oil or GLA insufficiency exists. Plasma fatty acid profiles can measure GLA and DGLA in research settings but are not standard clinical tests.
How it's corrected
Most gaps close with food first, and supplementation when a clinician recommends it.
Not applicable for deficiency. Borage oil is the highest-GLA plant oil, offering approximately 230–260 mg GLA per gram of oil versus evening primrose oil at roughly 80–100 mg GLA per gram. Clinical trial doses for rheumatoid arthritis and eczema have used approximately 1.4–3.0 grams of GLA per day from borage oil. Topical borage oil preparations have also been studied for eczema. Always select PA-free (UPA) certified borage oil products.
How to keep levels up
Not applicable. Adequate dietary linoleic acid (sunflower and safflower oils, nuts, seeds) supports endogenous GLA synthesis. Choosing PA-free certified borage oil is the key safety preventive measure.
When to see a clinician
For any liver symptoms (jaundice, right upper quadrant pain, fatigue with dark urine) — especially if using a non-PA-free borage oil product; hepatotoxicity from PAs is a genuine risk with poor-quality products. For drug interactions: discuss with a pharmacist before use if on anticoagulants, antiplatelets, phenothiazines (GLA may lower seizure threshold), or anticonvulsants.
Borage Oil Has the Highest GLA of Any Plant Oil — But No Deficiency Syndrome and a Real Safety Concern
Borage oil is the most concentrated plant source of gamma-linolenic acid (GLA) you can buy, but it is not an essential nutrient, and searching for a 'deficiency' is looking for something that doesn't exist.
GLA is a metabolic intermediate, not an essential fatty acid. Your body makes it from dietary linoleic acid—the omega-6 fat abundant in sunflower, safflower, and soybean oils—using an enzyme called delta-6-desaturase. Borage oil simply provides a pre-formed version, bypassing that enzymatic step. With a GLA content of roughly 20–26% of total fatty acids, borage oil is significantly more potent than its closest relatives: evening primrose oil at about 8–10% GLA and black currant seed oil at roughly 15–20%.
This concentration advantage is real and practical—you need less oil to get a therapeutic dose of GLA. But the trade-off is a safety concern unique to borage: pyrrolizidine alkaloid contamination. These are hepatotoxic and potentially carcinogenic compounds naturally present in the borage plant that can end up in the oil if it is not properly purified. This risk is almost entirely absent from wellness content promoting borage oil, and it transforms product selection from a preference into a safety necessity.
- Borage oil GLA content: ~20–26% of total fatty acids
- Evening primrose oil GLA content: ~8–10%
- Black currant seed oil GLA content: ~15–20%
- GLA is synthesized endogenously from linoleic acid—it is not an essential fatty acid
- No RDA, AI, or EAR exists for GLA or borage oil
Bottom line
Borage oil has the highest GLA content of any plant oil—a real practical advantage—but comes with a pyrrolizidine alkaloid safety concern that makes product selection (PA-free certified) essential; no deficiency syndrome exists.
The GLA Evidence: Atopic Eczema and Rheumatoid Arthritis — Where the Research Is Strongest
The two conditions most studied for GLA supplementation are atopic eczema and rheumatoid arthritis, and the evidence for each is distinctly different in quality and consistency.
For atopic eczema, the rationale is that patients with atopic dermatitis may have impaired delta-6-desaturase activity, leading to reduced GLA production and abnormal skin lipid profiles. Supplementing with GLA-rich oils is proposed to correct this, improving skin barrier function and reducing inflammation. However, the clinical trial evidence is mixed and complicated by a significant event: a 1993 Lancet paper on evening primrose oil for eczema was later retracted, casting doubt on earlier positive findings. Current consensus from the National Center for Complementary and Integrative Health is that GLA supplements have inconsistent effects on eczema. Some patients may experience modest improvements in itch and inflammation, but the evidence does not support a strong recommendation.
For rheumatoid arthritis, the evidence is more consistent, though still from relatively small trials. GLA competes with arachidonic acid in the inflammatory eicosanoid pathway, reducing the production of pro-inflammatory compounds. Several randomized controlled trials, including a notable 1993 study in the Annals of Internal Medicine, have shown modest but statistically significant improvements in joint tenderness and morning stiffness with GLA supplementation from borage oil. The effect is not dramatic—it is a modest adjunct, not a replacement for disease-modifying antirheumatic drugs—but the signal is more reliable than in eczema.
- RA evidence: modest, consistent improvements in joint tenderness and morning stiffness across multiple small RCTs
- Eczema evidence: mixed results, complicated by a major trial retraction; current consensus is inconsistent effects
- Neither condition has guideline-level recommendations for GLA supplementation
- GLA is not a replacement for standard dermatological or rheumatological care
Bottom line
The most honest verdict: RA is the better-supported use case for GLA supplementation (modest but consistent improvements); eczema evidence is mixed and complicated by a major trial retraction; neither constitutes strong RCT evidence at the scale that would drive guideline recommendations.
Pyrrolizidine Alkaloids: The Safety Concern That Consumer Content Always Omits
The single most important thing to know about borage oil—and the fact most consistently missing from supplement marketing and wellness content—is the risk of pyrrolizidine alkaloid contamination.
Pyrrolizidine alkaloids (PAs) are naturally occurring plant toxins found in borage (Borago officinalis). They are hepatotoxic, capable of causing veno-occlusive disease of the liver, and are considered mutagenic and potentially carcinogenic. The European Medicines Agency and the European Food Safety Authority have both issued regulatory opinions on PA contamination in herbal products, and some European countries have restricted borage oil products that lack certification as unsaturated pyrrolizidine alkaloid-free (UPA-free).
The risk is not theoretical. Improperly processed borage oil can contain significant levels of PAs. High-quality products are certified UPA-free, meaning they have been tested and confirmed to contain no detectable unsaturated pyrrolizidine alkaloids. When purchasing borage oil, look for explicit UPA-free certification, third-party testing, and compliance with European Pharmacopoeia standards. A product that does not prominently display its PA-free status should be avoided. This is not a matter of preference—it is a matter of liver safety.
- PAs are hepatotoxic, mutagenic, and potentially carcinogenic
- European Medicines Agency and EFSA have issued regulatory opinions on PA contamination
- Always select borage oil products that are explicitly certified UPA-free (unsaturated pyrrolizidine alkaloid-free)
- Look for third-party testing and European Pharmacopoeia compliance
- Non-certified borage oil products carry a genuine liver toxicity risk
Bottom line
Pyrrolizidine alkaloid contamination is a real and documented hepatotoxicity risk from borage oil—always buy UPA-free certified products; this risk is entirely absent from wellness and supplement marketing content.
Delta-6-Desaturase Impairment: The Physiological Rationale for GLA Supplementation
The most accurate way to understand who might benefit from borage oil is not through the lens of deficiency, but through the lens of impaired enzymatic conversion.
Delta-6-desaturase is the enzyme that converts dietary linoleic acid into GLA. Its activity is reduced in several common conditions: aging, type 2 diabetes, high dietary intake of trans fats and saturated fats, excessive alcohol consumption, and deficiencies in zinc and magnesium, which serve as enzyme cofactors. In these contexts, the body's ability to produce its own GLA is compromised, and supplementation with pre-formed GLA from borage oil may partially bypass the bottleneck.
This is the honest 'who benefits' framing. It is not that these individuals have a borage oil deficiency—they have a metabolic vulnerability that GLA supplementation might address mechanistically. This is particularly relevant for the population with metabolic syndrome and type 2 diabetes, where delta-6-desaturase impairment is well-documented. However, this remains a mechanistic rationale, not proof of clinical benefit, and supplementation decisions should be made in consultation with a clinician.
- Delta-6-desaturase activity is reduced by: aging, type 2 diabetes, high trans-fat intake, excessive alcohol, zinc/magnesium deficiency
- Impaired enzyme function means reduced endogenous GLA synthesis
- Pre-formed GLA from borage oil bypasses the enzymatic bottleneck
- This is a mechanistic rationale, not a proven clinical indication
Bottom line
The physiological rationale for borage oil supplementation is impaired delta-6-desaturase activity (in diabetics, older adults, high-trans-fat dieters)—not a deficiency state; this is a more mechanistically accurate framing than 'low GLA deficiency.'
Borage Oil and GLP-1 Therapy: Metabolic Syndrome, Inflammation, and the PA Safety Warning
The GLP-1 therapy population—people taking semaglutide, tirzepatide, or related medications for type 2 diabetes or obesity—has a high prevalence of the very conditions that create a mechanistic rationale for GLA supplementation, but also faces amplified safety concerns.
Metabolic syndrome and type 2 diabetes are associated with impaired delta-6-desaturase activity, meaning the population most likely to be on GLP-1 medications is also the population with the strongest biological rationale for GLA supplementation. Additionally, GLP-1 medications have anti-inflammatory effects, and GLA from borage oil may offer additive anti-inflammatory potential through the DGLA-to-eicosanoid pathway. However, no clinical trials have tested this combination, and the theoretical synergy remains unproven.
The safety concerns are more concrete. GLA at high doses may reduce platelet aggregation, potentially potentiating the effects of anticoagulant and antiplatelet medications. This is directly relevant to GLP-1 patients with cardiovascular disease who are often on aspirin, warfarin, or clopidogrel. GLA may also lower the seizure threshold in patients taking phenothiazine antipsychotics, which is relevant for patients with comorbid psychiatric conditions. Most critically, GLP-1 patients are frequently on multiple hepatically metabolized medications—metformin, statins, and others—making the liver toxicity risk from PA-contaminated borage oil a compounding concern. No pharmacokinetic interaction between borage oil and semaglutide or tirzepatide has been established, but the PA hepatotoxicity risk alone warrants caution and strict product selection.
- GLP-1 population has high prevalence of delta-6-desaturase impairment—mechanistic rationale exists
- No clinical trials have tested borage oil with GLP-1 medications
- Anticoagulant/antiplatelet interaction: GLA may potentiate bleeding risk
- Phenothiazine interaction: GLA may lower seizure threshold
- PA hepatotoxicity risk is compounded in patients on multiple hepatically metabolized drugs
- Use only PA-free certified products; discuss with clinician before combining
Bottom line
GLP-1 patients with metabolic syndrome have a biological rationale for GLA supplementation (impaired delta-6-desaturase)—but the PA hepatotoxicity risk, anticoagulant interaction, and phenothiazine interaction make product selection and pharmacist review essential before adding borage oil.
What most pages leave out
The pyrrolizidine alkaloid contamination concern is completely absent from virtually all wellness and supplement content on borage oil—this is the most significant competitor honesty failure. The second gap: the eczema evidence is weaker than commonly presented, complicated by a major trial retraction; the RA evidence is more consistent but still from small trials. The 'highest GLA content' claim is accurate and relevant but does not translate to superior efficacy without head-to-head clinical comparisons.
We flag this so you can make an informed choice — not to scare you off.
❓Frequently Asked Questions
There are no symptoms of borage oil deficiency because borage oil is not an essential nutrient and no deficiency syndrome exists. Eczema and joint inflammation are not caused by borage oil insufficiency—they are inflammatory conditions that may respond modestly to GLA supplementation in some patients.
Borage oil has significantly higher GLA content, typically 20–26% of total fatty acids compared to 8–10% in evening primrose oil, making it a more potent source of GLA per gram. However, borage oil also carries a pyrrolizidine alkaloid contamination risk that evening primrose oil does not share.
Evidence is mixed. Some trials show modest benefit in atopic dermatitis, but a major trial was retracted, and current consensus is that GLA supplements have inconsistent eczema effects. Dermatological treatment remains the evidence-based first-line approach.
Borage oil is only safe if it is PA-free (UPA) certified. Pyrrolizidine alkaloids in non-purified borage oil are hepatotoxic and potentially carcinogenic. Always select products that are certified free of unsaturated pyrrolizidine alkaloids.
Yes. GLA at high doses may reduce platelet aggregation, creating an interaction with anticoagulant and antiplatelet drugs. It may also lower the seizure threshold in patients taking phenothiazine antipsychotics. Discuss use with a pharmacist before starting borage oil if you are on these medications.
Clinical trials for rheumatoid arthritis and eczema have used approximately 1.4–3.0 grams of GLA per day from borage oil. Because borage oil has a higher GLA concentration than other oils, a lower volume of oil is needed to reach this therapeutic dose.
People with impaired delta-6-desaturase activity, such as those with type 2 diabetes, older adults, and individuals with high-trans-fat diets, have the strongest mechanistic rationale for use. Those with inflammatory joint conditions or severe atopic eczema not responsive to standard treatment may also consider it, but should discuss it with a clinician first.
There is no established benefit for combining borage oil with GLP-1 therapy. The pyrrolizidine alkaloid hepatotoxicity concern is particularly relevant for patients on multiple medications. Discuss with a clinician and use only PA-free certified products if you choose to take it.
Medically reviewed by
Chet Tharpe, MDBoard-certified physician
Last reviewed July 2026
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