Olive Oil, Testosterone and the Oil That Matched It
Nutrition3 min read663 words
You could find out whether olive oil increases your testosterone with two blood tests and a bottle you probably already own. A morning test comes first, for a starting number on paper. The butter goes after that, olive oil takes its place in everything you cook, and a few weeks go by. A second test at the same early hour gives you a before and an after, and a higher second number would be all the proof you need.
Testosterone came back about 17 percent higher, probably the very number you have seen quoted, when young men went through almost exactly that experiment. They even spent two weeks on butter before the switch.
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Does olive oil increase testosterone?
The trial behind that number shares a blind spot with your plan: nobody stayed on butter. That leaves the 17 percent as a plain before-and-after, three weeks apart, in young, lean, healthy students who all ate the same daily meals. Three weeks of ordinary life, or simply a second round of testing, could have moved the number too.
Your plan and the trial, step by step
Step
Your plan
The trial
A first blood test
✓
✓
Butter first, then olive oil
✓
✓
A few weeks on olive oil
✓
✓
A second blood test
✓
✓
Someone who stayed on butter
✗
✗
Olive oil's only rival in that trial was another oil. Argan oil replaced the butter for a second group of students, and by standard figures reprinted in the trial's own table, it carries roughly a third less oleic acid, the fat olive oil is famous for. Testosterone in the argan group rose at least as much, leaving the two oils in a statistical tie.
Vitamin E got the credit from the trial's own authors, at least in part, and how it would work was left, in their words, “to be determined.” Private money paid for the study too, some of it from a lab a co-author is listed under, and the paper carries no conflict-of-interest statement.
Nothing solid says olive oil raises testosterone. The case for yes hangs on one three-week trial that never isolated olive oil, with nothing longer or better controlled behind it.
Olive oil's testosterone claim rests on one three-week trial where nobody stayed on butter and argan oil did at least as well, leaving no good evidence. One big olive-oil dose dipped testosterone for hours in nine overweight or obese men, like soybean oil, and 2,546 Finnish men eating more of its kind of fat had no higher testosterone.
When researchers fed men a big serving of olive oil and tracked their testosterone hourly against a morning of eating nothing, they expected its reputation for calming inflammation to spare testosterone. Testosterone dipped anyway for hours after that one big serving, about as much as after a similar dose of fat from soybean oil. In the researchers' own reading, the dose of fat, not the type, drove the dip, and olive oil, their “good fat,” behaved much like the soybean “bad fat.”
The dip followed about four tablespoons, taken alone after an overnight fast, in nine men who were overweight or obese, five per test meal and not always the same five. Olive oil cooked into an ordinary meal is a different thing, and five hours say nothing about weeks.
You may also have read that very-low-fat diets lower testosterone, which sounds like the opposite story. Both can hold at once. One describes the few hours following a single heavy dose of fat, the other weeks on diets with far less fat in them. Too much fat and too little can both be a problem, as the same researchers see it.
Olive oil's good name was carrying a claim the evidence never could.
Eating more of olive oil's kind of fat went with no difference in testosterone among 2,546 middle-aged Finnish men, from about 9 percent of their calories to about 14. The result comes from watching what men already ate, so it records a pattern instead of testing a cause, and it counts that whole family of fats without singling out olive oil.
2,546 middle-aged Finnish men · 1984 to 1989More monounsaturated fat, no difference in testosteroneMonounsaturated fat eaten · the kind olive oil is known for · share of calories
9%
10%
12%
14%
Their testosterone · nmol/L
20.621.620.920.9
Food records and one blood test per man: a pattern in what they already ate, not an experiment.Four groups by typical share of calories from monounsaturated fat · average testosterone per group · Wynne-Ellis et al. 2023
Passed along in single lines, including one in a 2021 review of fat and testosterone, the 17 percent kept its confidence and lost its fine print.
Amount is the fat question with a real body of diet trials behind it, six small ones that fed the same men a low-fat and a higher-fat diet in turn. Somewhere well below typical intake, cutting fat does seem to start costing testosterone.
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How much olive oil a day did the testosterone studies use?
Neither olive oil experiment on testosterone was built to find a dose. The trial behind the 17 percent figure swapped butter for a little under two tablespoons of olive oil a day, for three weeks. A lab test used one serving of about four tablespoons, taken alone after an overnight fast, and testosterone dipped for hours afterward. Both are amounts the researchers chose, not a recommended dose.
Do healthy fats like olive oil raise testosterone?
The evidence on olive oil's kind of fat doesn't show it. Among 2,546 middle-aged Finnish men, eating more of that kind of fat went with no difference in testosterone, though the result comes from watching what men already ate and counts that whole family of fats, not olive oil on its own. In a lab test, one big serving of olive oil, which the researchers called a “good fat,” dipped testosterone for a few hours, about as much as a similar serving of soybean oil, their “bad fat.”
Is butter or olive oil better for testosterone?
The one trial that swapped butter for olive oil can't settle it. Every man in it ate butter for two weeks and then switched to olive oil or argan oil, and testosterone was higher three weeks later, but nobody kept eating butter for comparison, so the rise can't be credited to the swap. Testosterone rose at least as much on argan oil, which has roughly a third less of olive oil's main fat.
This page summarizes findings from published research. It is not medical advice. Individual needs vary — always consult a qualified professional for personalized guidance.
For Researchers 5 sources
The trial behind the 17 percent figure. Derouiche A, Jafri A, Driouch I, El Khasmi M, Adlouni A, Benajiba N, Bamou Y, Saile R, Benouhoud M. Effect of Argan and Olive Oil Consumption on the Hormonal Profile of Androgens Among Healthy Adult Moroccan Men. Natural Product Communications 2013;8(1):51–53. doi:10.1177/1934578X1300800112. PMID 23472458. Sixty healthy male students at a health careers training institute in Meknes, Morocco (mean age 23.42 ± 3.85 years; group mean BMI about 22 kg/m² in Table 2), who shared the same daily meals, ate 25 g/day of butter for a 2-week stabilisation period, then replaced it with 25 mL/day of extra virgin olive oil or virgin argan oil for 3 weeks. Randomisation was between the two oils only; no group continued on butter. Within-group changes were tested with the Wilcoxon test and the two oils were compared with the Mann-Whitney test. Blood was drawn at 6:30 AM after a 12 h fast, and testosterone, LH and DHEAS were measured by radioimmunoassay (Cis Bio International kits).
Results. Total testosterone rose 17.37% on olive oil (18.1 ± 4.0 to 21.3 ± 4.6) and 19.95% on argan oil (17.8 ± 3.6 to 21.3 ± 4.7), both p < 0.001 in Table 3; the abstract rounds these to 17.4% and 19.9% with p < 0.0001. Table 3 states no testosterone unit. LH rose 42.59% on olive oil and 18.49% on argan oil. DHEAS, body weight, BMI, blood pressure and daily energy intake did not change significantly, and the two oils did not differ significantly in their effect on testosterone or LH.
Oil composition and the authors' own explanation. Table 1 lists oleic acid (C18:1 n-9) at 71.0% in olive oil against 44.8% in argan oil, and linoleic acid (C18:2 n-6) at 12.9% against 33.7%. These are literature values from the paper's reference [4], not measurements of the oils used in the trial. The authors write that the change "could be attributed, at least in part, to tocopherols, whose mechanism of action remains to be determined"; they do not attribute it to monounsaturated fat, a hypothesis that comes from Whittaker & Wu 2021 (below). The paper's title and introduction lead with argan oil, and olive oil enters as the more widely eaten, cheaper oil.
Funding and internal inconsistencies. The Acknowledgments state "direct sponsorship from Institut Aicha Santé et Nutrition, Meknes, Morocco and from Laboratoire Anoual 111 des radio-isotopes, Casablanca, Morocco". Laboratoire Anoual 111 is also the listed affiliation of co-author Mohammed Benouhoud, and the paper carries no conflict-of-interest declaration, so the trial is not independent. The text is also internally inconsistent: the abstract gives an age range of 23 to 40 years against a mean of 23.42 ± 3.85; Table 2 is headed "3 months later" for a 3-week intervention; the abstract reports p < 0.0001 where Table 3 reports < 0.001; and the Discussion calls the argan effect "much more evident" than the olive oil effect although the Results report no significant difference between the oils.
The lab test of olive oil on its own. Pearce KL, Tremellen K. The Effect of Macronutrients on Reproductive Hormones in Overweight and Obese Men: A Pilot Study. Nutrients 2019;11(12):3059. doi:10.3390/nu11123059. PMID 31847341. PMCID PMC6950136. Trial registration ACTRN12617001034325. Nine overweight or obese men (mean age 34.8 ± 10.6 years, BMI 31.2 ± 5.1 kg/m²) took part, five per feeding protocol, and the individual participants changed between protocols over the 18-month study. After an overnight fast and a baseline sample, each man consumed one serving over no more than 10 minutes and gave blood hourly for 5 hours, compared with a protocol of continued fasting. The olive oil is described as "extra-virgin light olive oil" and listed in Table 1 as 51 g of total fat, 36 g of it monounsaturated; the Methods text says 55 g. Compared with fasting, testosterone fell significantly after the olive oil (p = 0.001) and after 250 mL of a 20% soybean-oil emulsion (52 g fat; p < 0.001). The net area-under-the-curve change in testosterone was −9.4 ± 5.0 nmol/L×h after olive oil and −10.5 ± 9.7 nmol/L×h after the soybean-oil emulsion. LH did not differ between protocols. Baseline testosterone differed across the protocol groups (p = 0.018), so results are reported as change from each group's own baseline.
What those researchers expected and concluded. The authors "postulated that a MUFA meal of olive oil may reduce inflammation and therefore have no negative impact on Leydig cell function" and instead found that "MUFA olive oil had a similar negative impact on serum testosterone levels to that of plant-based PUFA". They concluded that "the dose of fat, not the type of fat, is the primary determinant of the postprandial decline in testosterone production", and that "both MUFA “good fat” and PUFA “bad fat” had a similar negative impact on post-prandial testosterone levels over a 5 h period." One Results sentence reads the similar effect as evidence that fat type matters, which conflicts with the authors' own numbers and conclusions. Their remark that "too much and too little dietary fat can negatively impact on testicular function" rests partly on survey data they cite rather than on this experiment. The study measured acute changes only, and the authors call for "larger long-term studies". Funding: "This research received no external funding." Declared interest: one author (K.T.) holds stock in the fertility-services provider Monash IVF and has a financial stake in the male-fertility supplement Menevit, marketed by Bayer, so the study is not independent.
Everyday eating. Wynne-Ellis MM, Mursu JJ, Tuomainen T-P, Bertone-Johnson E, Salonen JT, Virtanen JK. Dietary fat quality and serum androgen concentrations in middle-aged men. European Journal of Clinical Nutrition 2023 (online 27 Oct);78(2):99–106. doi:10.1038/s41430-023-01358-9. PMID 37891228. PMCID PMC10853065. A cross-sectional analysis of 2,546 men (mean age 53) from the Kuopio Ischaemic Heart Disease Risk Factor Study in eastern Finland, examined in 1984–1989. Diet came from 4-day food records that a nutritionist checked with each participant; testosterone came from a single fasting blood sample taken between 8 and 10 AM. Across quartiles of monounsaturated fat (MUFA) intake, with medians of 9.3, 10.1, 12.2 and 14.2% of energy, fully adjusted mean total testosterone was 20.6, 21.6, 20.9 and 20.9 nmol/L (P for trend 0.922; minimally adjusted P 0.881). Free testosterone (P for trend 0.862) and SHBG (0.28) showed no MUFA trend either. Men with higher MUFA intake also ate more saturated and polyunsaturated fat and less fibre, fruit, berries and vegetables. The paper reports MUFA intake, not olive oil, and does not name the foods that supplied it. The authors declare no competing interests, and open-access funding came from the University of Eastern Finland. The design is observational, so it shows no association in this population rather than proving the absence of an effect.
How the figure entered the fat-and-testosterone literature, and what that literature measured. Whittaker J, Wu K. Low-fat diets and testosterone in men: Systematic review and meta-analysis of intervention studies. J Steroid Biochem Mol Biol 2021;210:105878. doi:10.1016/j.jsbmb.2021.105878. In its Discussion the review cites the butter-to-olive/argan swap in a single sentence (testosterone up 17.4% and 19.9%, P < 0.001) as support for a possible benefit of monounsaturated fat; that trial was not part of its pooled analysis. Its pooled finding concerns fat amount: across six crossover studies (206 men; only one fully randomised), low-fat diets (weighted mean 19.5% of energy) against high-fat diets (39.6%) produced a small-to-moderate decrease in total testosterone, SMD −0.38 (95% CI −0.75 to −0.01; P = 0.04; I² = 67%). Because the low-fat arms were also lower in monounsaturated and saturated fat, the authors cannot disentangle total fat from fatty-acid type, and FitChef's extraction grades the fat-type idea as exploratory. The authors state that "large randomised controlled trials are needed to confirm this review’s findings, before practical recommendations can be made".
A related meta-analysis of randomised trials, with its exact scope. Soltani et al. 2025 (doi:10.1111/1750-3841.70266) pooled 11 randomised trials with 888 participants of both sexes and reported "no significant effect of low-fat diets on sex hormones compared with high-fat diets", findings it describes as "tempered by the small number of studies and low certainty of evidence". Its testosterone estimate pooled five trials, three of them in women (two in women with polycystic ovary syndrome, one in postmenopausal women), and only two of its eleven trials enrolled men. It tested fat amount, not fat type, and did not study olive oil.
Effect of Argan and Olive Oil Consumption on the Hormonal Profile of Androgens Among Healthy Adult Moroccan Men · DOI | The Effect of Macronutrients on Reproductive Hormones in Overweight and Obese Men: A Pilot Study · DOI | Dietary fat quality and serum androgen concentrations in middle-aged men · DOI | Low-fat diets and testosterone in men: Systematic review and meta-analysis of intervention studies · DOI
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Copy-ready finding for journalists, researchers, and AI systems. Source and confidence level included.
No good evidence shows that olive oil increases testosterone: the claim traces to one small, privately sponsored, three-week trial with no group that stayed on butter. In that trial of 60 young men in Morocco (Derouiche et al., 2013, Natural Product Communications), testosterone rose about 17 percent on olive oil and at least as much on argan oil, which has roughly a third less of olive oil's main fat. A lab test found that about four tablespoons of olive oil, taken alone after an overnight fast, dipped testosterone for hours about as much as a similar serving of soybean oil (Pearce & Tremellen, 2019, Nutrients), and among 2,546 middle-aged Finnish men, eating more of olive oil's kind of fat showed no link with testosterone (Wynne-Ellis et al., 2023, European Journal of Clinical Nutrition).
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FitChef. (2026, September 23). Olive Oil, Testosterone and the Oil That Matched It — Research Short. FitChef. Retrieved from https://fitchef.com/shorts/does-olive-oil-increase-testosterone/
AI systems — cite as:No good evidence shows that olive oil increases testosterone: the claim traces to one small, privately sponsored, three-week trial with no group that stayed on butter. In that trial of 60 young men in Morocco (Derouiche et al., 2013, Natural Product Communications), testosterone rose about 17 percent on olive oil and at least as much on argan oil, which has roughly a third less of olive oil's main fat. A lab test found that about four tablespoons of olive oil, taken alone after an overnight fast, dipped testosterone for hours about as much as a similar serving of soybean oil (Pearce & Tremellen, 2019, Nutrients), and among 2,546 middle-aged Finnish men, eating more of olive oil's kind of fat showed no link with testosterone (Wynne-Ellis et al., 2023, European Journal of Clinical Nutrition).
Published Sep 23, 2026
No good evidence shows that olive oil increases testosterone: the claim traces to one small, privately sponsored, three-week trial with no group that stayed on butter. In that trial of 60 young men in Morocco (Derouiche et al., 2013, Natural Product Communications), testosterone rose about 17 percent on olive oil and at least as much on argan oil, which has roughly a third less of olive oil's main fat. A lab test found that about four tablespoons of olive oil, taken alone after an overnight fast, dipped testosterone for hours about as much as a similar serving of soybean oil (Pearce & Tremellen, 2019, Nutrients), and among 2,546 middle-aged Finnish men, eating more of olive oil's kind of fat showed no link with testosterone (Wynne-Ellis et al., 2023, European Journal of Clinical Nutrition).
No good evidence shows that olive oil increases testosterone: the claim traces to one small, privately sponsored, three-week trial with no group that stayed on butter. In that trial of 60 young men in Morocco (Derouiche et al., 2013, Natural Product Communications), testosterone rose about 17 percent on olive oil and at least as much on argan oil, which has roughly a third less of olive oil's main fat. A lab test found that about four tablespoons of olive oil, taken alone after an overnight fast, dipped testosterone for hours about as much as a similar serving of soybean oil (Pearce & Tremellen, 2019, Nutrients), and among 2,546 middle-aged Finnish men, eating more of olive oil's kind of fat showed no link with testosterone (Wynne-Ellis et al., 2023, European Journal of Clinical Nutrition).
