Are SSRIs Safe To Take With Chlorella Supplements?

In our latest question and answer, our pharmacist discusses the safety of combining chlorella with SSRIs like Paxil.

Question

Hello, Is it safe to take Paxil and chlorella together?

Asked by Billy On Jan 12, 2023

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Jan 12, 2023
Last updated Apr 30, 2025

Key points

  • Both chlorella and SSRIs (like Paxil) have been associated with causing photosensitivity (i.e., sun sensitivity). Taking both together could increase the risk.
  • This interaction in only theoretical based on published case studies and the risk of it occurring is thought to be very low. It is nevertheless important to know about.

Answer

Thanks for your question! Chlorella is a common ingredient used in dietary supplements, mainly for its nutritive value as it contains omega 3 and 6 fatty acids, several different vitamins (e.g., vitamin B6 and B12, iron, beta-carotene, and ascorbic acid), minerals and antioxidants.

It also has other purported health benefits and has been used for a range of conditions, including depression (some studies suggest chlorella may improve the antioxidant imbalance seen in depression) and fibromyalgia, but more evidence is needed to determine whether or not it has positive benefits.

In terms of drug interactions, most are likely not clinically significant but it does have theoretical interactions with a few different types of drugs, such as:

  • Drugs that make you more sensitive to sunlight (i.e., photosensitizing drugs)
  • Anticoagulants, like warfarin

Chlorella With SSRIs

You specifically asked about Paxil (paroxetine), which is an SSRI (selective serotonin reuptake inhibitor).

Although seemingly rare, all SSRIs have been associated with causing photosensitivity, and there have been case reports of individuals having skin reactions to prolonged sun exposure while taking them.

One such study reported the following:

Although these drugs [SSRIs] are widely prescribed, such photosensitization is rare. Nevertheless, we consider that clinicians and patients should be aware of the risk of photosensitization and these drugs should be stopped before phototherapy or prolonged sun exposure.

Clin Exp Dermatol . 2009 Dec;34(8):e763-5.

Chlorella has also been reported as causing photosensitivity (i.e., sun sensitivity), but evidence has been limited to just a few case reports (such as reported in a study published in the International Journal of Dermatology).

So, theoretically, taking chlorella with other drugs that cause photosensitivity could further increase the risk of it occurring. Again, this would include all SSRIs, such as:

It must be noted that the overall risk of this interaction occurring is thought to be quite low, as photosensitivity has been reported with chlorella and SSRIs only rarely. Nevertheless, it is good to know about.

I mentioned that chlorella, as a dietary supplement, has sometimes been used for its purported antidepressant effects, which I can see being a concern if you already take an SSRI.

However, the purported antidepressant effect from chlorella isn't thought to be due to any changes in brain neurotransmitters, but rather, its antioxidant effects. As far as we know, there is no interaction between SSRIs and chlorella in regard to changes in serotonin and there doesn't appear to be any risk with serotonin syndrome (a common drug-interaction concern with antidepressants).

Final Words

I hope this provided the information you were looking for! Reach back out anytime.

References

  • Chlorella photosensitization. New phytophotodermatosis, PubMed
  • A randomized controlled trial of 6-week Chlorella vulgaris supplementation in patients with major depressive disorder, PubMed
  • Photosensitivity associated with selective serotonin reuptake inhibitors, PubMed

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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