What Vitamins Should Not Be Taken With HRT?
What vitamins should not be taken with HRT?
Hormone replacement therapy (HRT) is one of the most effective treatments for managing the symptoms of perimenopause and menopause. Many women taking HRT also take vitamins and supplements to support their overall health during this life stage. The two are generally compatible, but there are some specific combinations worth knowing about before you start adding new supplements to your routine.
Vitamins and supplements to be cautious about with HRT
St John's Wort
This is the most significant interaction to be aware of. St John's Wort is a herbal supplement widely used for low mood and mild depression. It is a potent inducer of CYP enzymes in the liver, which are responsible for metabolising many medications including oestrogen. Taking St John's Wort alongside HRT can accelerate the breakdown of oestrogen in the body, reducing the effectiveness of your HRT significantly. This is a well-documented interaction that your prescribing clinician will almost certainly advise you to avoid.
High-dose Vitamin E
Vitamin E at standard dietary doses is safe and well tolerated alongside HRT. However, very high doses of Vitamin E supplements have mild anticoagulant properties and may interact with the blood clotting effects associated with some forms of HRT, particularly oral oestrogen. If you are taking oral HRT and considering high-dose Vitamin E supplementation, discuss this with your GP first. Topical or transdermal HRT carries a lower risk of blood clotting effects and this interaction is less relevant for patches or gels.
High-dose Vitamin B6
Vitamin B6 at standard doses found in multivitamins and B complex supplements is safe alongside HRT. Very high supplemental doses of B6 taken over long periods can cause peripheral neuropathy and are generally not recommended regardless of HRT use. At the doses found in standard supplements, B6 is not a concern.
Soya isoflavones and phytoestrogens
Soya isoflavones and other phytoestrogen supplements act on oestrogen receptors in the body. When taken alongside HRT, they can potentially amplify oestrogenic effects in ways that are difficult to predict. Some women take phytoestrogen supplements as a natural alternative to HRT. Combining them with prescription HRT is not recommended without medical guidance, as the combined oestrogenic effect may be higher than intended.
Vitamins that are safe and beneficial alongside HRT
Vitamin D
Vitamin D is not only safe alongside HRT but is particularly important for women taking it. Oestrogen plays a role in calcium absorption and bone density maintenance. As HRT supports oestrogen levels, Vitamin D works synergistically to support bone health alongside it. Vitamin D deficiency is extremely common in the UK year-round and supplementation is recommended for most adults regardless of HRT status.
Magnesium
Magnesium is safe and beneficial alongside HRT. It supports sleep quality, mood regulation, energy production and bone health, all of which are commonly affected during perimenopause and menopause. There are no known interactions between magnesium and HRT medications.
Vitamin C
Vitamin C is safe alongside all forms of HRT. It supports immune function, skin health and collagen synthesis. It is also an essential co-factor for collagen production, meaning it works directly with collagen supplements to maximise their effectiveness.
B vitamins
B vitamins at standard supplement doses are safe alongside HRT. B vitamins support energy metabolism, nervous system health and mood, making them particularly relevant during perimenopause when fatigue and cognitive changes are common. Kollo Balance+ includes a full B vitamin complex specifically formulated for this life stage.
Collagen
Marine collagen supplements are completely safe alongside all forms of HRT. Collagen is a protein derived from fish. It has no hormonal activity and no known interactions with any form of HRT. Collagen supplementation is particularly relevant for women taking HRT because oestrogen plays a role in collagen synthesis. As oestrogen declines, collagen production accelerates its natural decline. HRT helps address the hormonal side of this, while collagen supplementation directly provides the structural building blocks the body needs.
Omega 3
Fish oil and omega 3 supplements are safe alongside HRT. They support cardiovascular health, joint health and mood, and have no known interactions with HRT medications at standard doses.
What vitamins can you take with HRT patches specifically?
Transdermal HRT delivered through patches or gels has a lower first-pass metabolism effect than oral HRT, meaning the oestrogen bypasses the liver before reaching the bloodstream. This makes transdermal HRT less susceptible to interactions with enzyme-inducing supplements like St John's Wort, though the interaction is not entirely eliminated and caution is still advised.
For women using HRT patches, the same general guidance applies. Vitamin D, magnesium, B vitamins, Vitamin C, omega 3 and collagen are all compatible with patch-based HRT. St John's Wort and high-dose phytoestrogens remain the combinations most worth discussing with your GP.
Does HRT deplete vitamins?
There is some evidence that oestrogen-based HRT may affect the metabolism of certain B vitamins, particularly B6 and folate, in ways that could increase requirements slightly. This is one reason why ensuring adequate B vitamin intake is particularly important for women on HRT. A good quality B complex supplement or a formula like Kollo Balance+, which includes a full B vitamin complex alongside targeted menopause botanicals, helps ensure these bases are covered.
HRT does not deplete Vitamin D, magnesium, Vitamin C or collagen-related nutrients in any clinically significant way.
Building the right supplement routine alongside HRT
Many women find that HRT addresses the hormonal symptoms of menopause effectively, but want additional support for the physical changes that accompany this life stage. Collagen loss accelerates significantly during perimenopause and menopause, affecting skin, hair, nails, joints and bone density. HRT helps slow this process but does not reverse existing collagen loss.
- Kollo Premium Liquid Marine Collagen: 10,000mg Naticol® per day for skin, hair, joints and bone support
- Kollo Balance+: targeted liquid menopause formula with lion's mane, ashwagandha, sage, magnesium and B vitamins
- Vitamin D: essential for bone health and immune function, particularly in the UK where deficiency is common
- Omega 3: cardiovascular and joint support, safe alongside all HRT types
For a complete guide to supplements during this life stage, read our guide to the best supplements for women over 40 and our complete guide to menopause supplements.
Kollo Health was co-founded by Jenni Falconer - TV presenter, Smooth Radio breakfast host, ten-time London Marathon runner and host of the RunPod podcast. Read her story and why she created Kollo.
