Humic Acid Complexes

We evaluated 71 human studies on Humic acid complexes, including 19 randomised controlled trials and 3 meta-analyses or systematic reviews; the controlled studies include 1,611 participants in total. As of 3 October 2026.

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1. What Is Humic Acid Complexes? Occurrence, Origin and Forms

Humic acid complexes are mixtures of large organic molecules that form when dead plant matter is broken down and transformed over long periods – above all lignin, the woody substance of plants. There is no single, uniform humic acid: origin, degree of maturation and extraction determine which molecules a preparation contains. They are divided into humic acids, fulvic acids and humins.

Humic acid complexes occur in soils, in peat and bog, in brown coal and leonardite, in compost and in rivers, lakes and their sediments. Shilajit, also called mumijo, is a resin-like substance that seeps from rock in high mountain ranges such as the Himalayas and the Altai and consists largely of humic substances.

Preparations taken by mouth are mostly obtained from leonardite, brown coal or peat: the humic substances are dissolved with alkali, separated and purified. Shilajit is purified and dried. There is also fulvic acid manufactured from carbohydrates (carbohydrate-derived fulvic acid, CHD-FA). Baths and packs use medicinal peat.

Forms and Preparations Studied

• Humic acids and humates, such as sodium or potassium humate
• Fulvic acid, including carbohydrate-derived fulvic acid (CHD-FA)
• Shilajit (mumijo, momiai, asphaltum, mineral pitch)
• Drinkable peat and peat extracts taken by mouth
• Peat baths, peat packs and peloids made from peat
• Combination products containing humic acid complexes – the other ingredients are named in each case

Not covered on this page:

• Sulphur, brine, radon and mineral baths without peat, and mineral mud (fango) without peat → Balneotherapy and Moor Therapy
• Humus as a soil parameter in agricultural and environmental studies
• Isolated lignin from the wood and paper industry

2. What Does Humic Acid Complexes Do? Results by Area

How to read the table: counted are human studies whose results concern the area. “High” means at least one meta-analysis and two controlled studies showing improvement, or at least three controlled studies of which three quarters show improvement, with at least 300 participants in total. “Moderate” means at least two controlled studies showing improvement, as a majority, or one meta-analysis alongside controlled studies. “Low” means one controlled study showing improvement. Where an area has no controlled study, the strength of evidence is at most “low” (result “reviews only” or “observational data only”). Everything else is “unclear”. A study counts as showing improvement when at least half of its outcomes in this area improved. Reviews of combination products do not count as meta-analyses; results that only describe side effects or shares of users do not count as an effect. The same study is counted only once.

3. What the Studies Show in Detail

Humic Acid Complexes, Bones, Joints and Muscles: Human Studies

For bones, joints and muscles, peat applications relieved pain in controlled studies: in knee osteoarthritis under peat packs compared with a mere hot pack 19 and under peat compresses compared with a sham treatment 26, in back pain under peat pack plus trunk training compared with training alone 20. In another study on back pain, pain and mobility improved under peat therapy as well as under ultrasound and magnetic therapy; for pain, ultrasound performed best 27. A meta-analysis on mud therapy, which included peat in addition to clay and mineral mud, found less pain and better physical function 1. Under shilajit, muscle strength increased in randomized studies 6 and fatigue-related loss of strength decreased 21; after a tibial fracture, the bone healed faster under mumijo (Momiai) 5. Oral potassium humate relieved pain in knee osteoarthritis in a small randomized study 14. The strength of evidence is high, but many studies are small, and the comparison conditions as well as the composition of the preparations differ considerably.

Further studies in this area: 20 21 25 26 27 33 34 36 39 41 49 50 53 54 55 56 62 68

Humic Acid Complexes, Hormones and Fertility: Human Studies

In men, testosterone increased under shilajit in three randomized studies 6722; a systematic review classifies shilajit as possibly effective in men with late-onset hypogonadism 3. One study also found a better sexual response 7, another an increase in DHEAS with unchanged levels of LH and FSH 22. A mixed preparation of shilajit with ashwagandha, ginger, black pepper, Mucuna pruriens and akarkara also improved free and total testosterone in a randomized controlled study 8. The strength of evidence is high, but the studies tested almost exclusively shilajit in men; for peat bath, drinkable peat and other humic acid complexes as well as for women, hardly any robust data are available.

Humic Acid Complexes, Energy, Performance and Fatigue: Human Studies

In two randomized studies in men, shilajit improved muscular endurance and lowered perceived exertion 6; in the other, maximal oxygen uptake increased, and fatigue decreased somewhat more than under placebo 7. A mixed preparation of shilajit and herbs improved endurance in strength exercises 8. The strength of evidence is high, but the controlled studies predominantly tested shilajit alone or in mixtures, mostly included healthy, trained men and were partly small; for humic acids, fulvic acid, drinkable peat or medicinal peat as a single preparation for fatigue, controlled data are lacking.

Further studies in this area: 57 63 69

Humic Acid Complexes, Inflammation and Immune System: Human Studies

In hay fever and atopy, skin test reactions weakened in two small randomized studies, with fulvic acid (CHD-FA) 13 and with oral potassium humate 11; in the potassium humate study, the eosinophil count also decreased, while immune cell functions such as neutrophil adhesion and basophil stimulation remained unchanged 11. The strength of evidence is moderate: the controlled studies are small, some without a placebo group, and the larger investigations concern combination preparations or other diseases. Oral humates and fulvic acid, peat applications, and mixtures were studied; for peat baths, drinkable peat, and shilajit as a single preparation, predominantly uncontrolled observations are available, and a case report describes an exercise-induced anaphylaxis in which shilajit was considered a co-trigger 44.

Further studies in this area: 44 46 47 49 51 57 60 62 64

Humic Acid Complexes, Metabolism and Blood Sugar: Human Studies

A randomized study with shilajit gummies found no difference in body weight, BMI, and waist circumference 7. A study with a mixture of shilajit and agnimantha showed a lower body mass (BMI) and lower total cholesterol compared with another herbal preparation 9. The strength of evidence is moderate; it remains open whether the effects are due solely to the humic acid complexes and whether they can be confirmed in healthy people.

Further studies in this area: 57 58

Humic Acid Complexes, Skin and Wounds: Human Studies

In eczema, the investigators assessed the response with fulvic acid (CHD-FA) for topical application as better than with a plain care cream in a small randomized study; however, severity and redness improved in both groups 12. A controlled, non-randomized study with oral shilajit found better skin blood flow and altered activity of genes for connective tissue and vessels in middle-aged women 30. The strength of evidence is moderate; the studies are small, and the shilajit study is not randomized. It remains open whether the findings apply to other preparations and over longer periods.

Humic Acid Complexes, Digestion and Gut: Human Studies

For digestion and the gut, two controlled studies are available. In people with diarrhea-predominant irritable bowel syndrome, a randomized study found no confirmed difference from placebo with humic acids 18. Women responded better than men 18. A wellness drink with fulvic acid (CHD-FA) was overall well tolerated in a controlled study of 332 HIV-positive people 23. However, gastrointestinal complaints occurred more frequently with it than with placebo 23. The strength of evidence is overall unclear, as the controlled findings do not give a consistent picture. Reliable statements about digestive complaints cannot be derived from this.

Humic Acid Complexes, Brain and Cognition: Human Studies

For the brain and mental performance, only observations without a control group are available for humic acid complexes. A study without a comparison group reports a better mood after rhythmic rubbing with Solum oil, a peat extract with lavender oil 35. Another study reports a better mood after a peat bath 37. Two review articles suggest benefits for mental performance from shilajit 54 and in neurodegenerative diseases from fulvic acid 64. Since no controlled studies and no meta-analyses are available, the strength of evidence is unclear; a peat extract-lavender oil mixture, a peat bath, shilajit, and fulvic acid were studied.

Humic Acid Complexes: Further Outcomes in Studies

After disc surgery, everyday resilience (Oswestry index) improved with peat mud applications 25, and in knee osteoarthritis, general health status improved with peat compresses 26. With shilajit, perceived stress 7 and signs of oxidative stress 10 decreased, and with mumijo, a lowered platelet count was less common 28. A randomized study with shilajit also showed lower muscle damage values (creatine kinase, lactate dehydrogenase) 6; with potassium humate, the liver value GGT temporarily rose in four participants, and with placebo in two 14. A meta-analysis on mud therapy, which also included peat, found no increase in serious adverse events 1. The strength of evidence is overall high, as several controlled studies are available; shilajit, mumijo, fulvic acid (CHD-FA), potassium humate, and peat applications were tested, some in combination preparations. The transferability to other humic acid complexes and the confirmation of the safety findings in larger, longer-term studies remain open.

Further studies in this area: 14 17 23 25 26 28 29 31 32 34 35 38 40 41 42 43 46 48 51 54 56 57 59 63 64 65 66

4. How Is Humic Acid Complexes Dosed? Preparation, Dose and Duration in Studies

The studies investigated mainly shilajit as capsules, gummies or resin, peat applications as baths, packs and peloids, as well as oral humates and fulvic acid. Some preparations were mixtures, such as shilajit with herbs or fulvic acid in a wellness drink. The doses and application durations are shown in the table.

5. Is Humic Acid Complexes Safe? Side Effects in Studies

The studies predominantly report good tolerability. More frequently mentioned were temporary skin redness and fatigue under mud and peat applications, briefly lasting burning under topical fulvic acid, as well as gastrointestinal complaints under a fulvic acid-containing drink. One case report describes an exercise-induced anaphylaxis in which shilajit was considered a co-trigger, and in one study the liver value GGT temporarily increased under potassium humate in four and under placebo in two participants.

6. What Remains Open: Limits of the Evidence

• Many studies are small and of short duration.
• The comparison conditions and the composition of the preparations differ considerably.
• For peat bath, drinkable peat and other humic acid complexes as a single preparation for fatigue, controlled data are lacking.
• Almost all studies on hormones and fertility tested shilajit in men; for women, hardly any robust data are available.
• It remains open whether the effects are due solely to the humic acid complexes or to other components of mixed preparations.

7. Bottom Line: What Is Established About Humic Acid Complexes

Humic acid complexes are not a uniform substance but mixtures of large organic molecules from decomposed plant material, primarily from lignin. Human studies show improvements for shilajit and peat applications in pain, physical function, muscle strength, testosterone, endurance performance and some skin and immune parameters. The strength of evidence is high for bones, joints and muscles, hormones as well as energy and performance, moderate for metabolism, skin and immune system, and unclear for digestion as well as brain. Many studies are small, the preparations differ greatly, and controlled data are lacking for several preparations.