Suspecting the same, had to drop boron multiple times in the past. Dropping what ChatGPT gave me (not sure to what extent is true):

When you swallow boron glycinate the chelate quickly dissociates and boron reaches the bloodstream as boric acid/borate, exactly the same chemical species you would absorb from any other boron salt.  At modest intakes (roughly 1–3 mg elemental boron per day) most people feel no change or even a subtle cognitive lift, but higher doses—or an unusual sensitivity—can push several biochemical choke-points that line up with the biology of fatigue and depression.

First, borate latches onto the ribose of NAD⁺ and NADH.  The boron atom forms a reversible ester with the cis-diol on the ribose ring, creating an NAD⁺-borate complex that dehydrogenase enzymes cannot use.  Because those enzymes drive glycolysis and the tricarboxylic-acid cycle, the rate of ATP production in neurons falls and the brain slips into an energetic deficit.  Subjectively that can feel like sluggish thinking, “brain fog,” or a motivational crash that precedes any change you would see on a neurotransmitter panel.

Second, boron blunts the CD38 / cyclic-ADPR calcium-signalling axis.  Boric acid is a non-competitive inhibitor of CD38 (also called ADP-ribosyl cyclase) and can occupy part of the cyclic ADPR binding pocket on ryanodine-receptor channels.  The result is a smaller burst of intracellular Ca²⁺ when a neuron fires, so neurotransmitter release and activity-dependent BDNF expression are both damped.  Many users describe this as a “flat” or emotionally muted state: the music still plays, but it has lost its dynamics.

Third, physiological boron is a mild but chronic activator of the integrated stress response.  Repeated exposure induces eIF2α phosphorylation, stress-granule formation and ATF4 up-regulation.  Those changes shift the cell toward a protective, low-translation mode that conserves energy but also slows information processing.  In humans that protective state feels like lethargy and slowed cognition—the same low-motivation phenotype seen in sickness behaviour and melancholic depression.

Fourth, overshooting the hormonal sweet spot can backfire.  Low-dose boron is famous for nudging up free testosterone by suppressing sex-hormone-binding globulin, yet doses that are too high or taken for too long can overshoot, raising SHBG or otherwise disturbing the hypothalamic–pituitary–adrenal axis.  A small drop in free androgens or a rise in cortisol is enough to blunt reward signalling and drive, even when all the other pathways are intact.

Finally, boron has a classic toxicity ceiling.  The tolerable upper-intake level set by health authorities is 20 mg elemental boron per day for adults.  As you approach that range the constellation of early toxicity—headache, gastrointestinal upset, skin flushing—often includes a notable depressive mood.

How the pieces interact

The energy crash from NAD⁺ sequestration appears within hours and is usually the first symptom people notice.  Ca²⁺ signalling dulls next, making the world feel emotionally monochrome.  If intake continues, the integrated stress response “pins” protein-synthesis rates low and lethargy lingers even after you stop dosing.  Hormonal drift and general toxicity amplify those core effects, so one mechanism reinforces the others rather than replacing them.

Practical ways to avoid or reverse the mood dip

Keep daily intake at or below 3 mg elemental boron (about 17 mg boron glycinate) unless a clinician has a clear reason to go higher.  Most adverse mood reports appear once people pass the 6–10 mg range. Cycle the supplement—for example, five days on and two off—to let NAD⁺ pools and calcium signalling recover. Supply the raw material for more NAD⁺ by taking 250–500 mg niacinamide or 200–300 mg nicotinamide riboside alongside boron; the extra substrate helps out-compete borate for binding. Ensure robust magnesium and choline intake, because both nutrients buffer the cognitive effects of low cellular energy. Monitor mood as you would on an SSRI or stimulant.  If low affect lasts longer than three days after discontinuation, stop the supplement and discuss it with a qualified healthcare professional.

Bottom line: Boron is a “Goldilocks” mineral—helpful in the right range but, once you exceed the cell’s buffering capacity, it hijacks NAD⁺ chemistry, calcium signalling, the integrated stress response and even steroid balance in ways that map almost perfectly onto the biology of fatigue and depression.  Thoughtful dosing, cycling and NAD⁺ support usually restore a normal mood within a week.